Explanation:
a)Take percentages and divide by mole wt ( from periodic table) of the corresponding element
C 14.25 / 12 = 1.1875
O 56.93 / 15.99 = 3.56
Mg 28.83/24.3 = 1.186 Divide by the smallest number
C 1.1875/1.186 = 1
O 3.56 / 1.186 = 3
Mg 1.186 / 1.186 = 1
C O3 Mg commonly written as Mg CO3 ( magnesium carbonate)
help please been asking for days LOLLL keep getting the wrong answers.
Answer:
22.24°C.
Explanation:
The change in temperature of the iron can be calculated using the formula: ΔT = Q / (m * c), where ΔT is the change in temperature, Q is the heat added, m is the mass of the substance and c is the specific heat capacity.
Substituting the given values into the formula: ΔT = 115 cal / (47.0 g * 0.11 cal/g⋅°C) ≈ 22.24°C
So, the change in temperature of the iron is 22.24°C.
What volume will 1.02 mol of carbon monoxide gas occupy at STP?
1.02 mol of carbon monoxide gas will occupy a volume of approximately 22.8 liters at STP.
At STP (standard temperature and pressure), the temperature is 273.15 K (0°C) and the pressure is 1 atmosphere (atm). The molar volume of a gas at STP is 22.4 L/mol.
Using the ideal gas law, we can calculate the volume of 1.02 mol of carbon monoxide gas at STP: PV = nRT
where:
P = pressure = 1 atm
V = volume (unknown)
n = moles = 1.02 mol
R = gas constant = 0.0821 L·atm/(mol·K)
T = temperature = 273.15 K
V = (nRT)/P
putting the values,
V = (1.02 mol)(0.0821 L·atm/(mol·K))(273.15 K) / (1 atm)
V = 22.4 L/mol
V = 22.8 L
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What is the base conjugate acid pair in this balanced equation NH3+HNO3→NH4+ + NO3-
Answer:
The base conjugate acid pair is NH3 and NH4+.
Which term describes the energy the reactant molecules must meet for a reaction to progress?
O average kinetic energy of reactants
O enthalpy
O activation energy
O average kinetic energy of products
Answer:
Activation Energy
Explanation:
Activation energy is the minimum amount of energy that reactant molecules must possess in order to undergo a chemical reaction. as it is necessary to break the bonds of between the molecules of the reactants.
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CAN SOMEONE HELP WITH THIS QUESTION?✨
The molarity of the sodium hydroxide solution is 0.0911 M.
We must figure out how many molecules of potassium hydrogen phthalate there are.
moles of KHP = mass / molar mass = 0.600 g / 204.22 g/mol = 0.00294 mol
We know that 0.00294 moles of NaOH were used in the titration because one mole of KHP interacts with one mole of NaOH. This data can be used to determine the molarity of the NaOH solution:
molarity of NaOH = moles of NaOH / volume of NaOH used in liters
volume of NaOH = 32.21 mL = 0.03221 L
calculation of the molarity of NaOH:
molarity of NaOH = 0.00294 mol / 0.03221 L = 0.0911 M
The molarity of the sodium hydroxide solution is 0.0911 M.
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What is the normality of the solution that results when 4.0g of Al(NO3)3 (MW = 213.0) is dissolved in enough water to give
250mL of solution? What is the molarity of the solution?
the normality of the solution that results when 4.0g of Al(NO₃)₃ (MW = 213.0) is dissolved in enough water to give 250mL of solution the molarity of the solution is 0.0751 M.
To calculate the normality and molarity of the solution, we need to know the number of moles of Al(NO₃)₃ in the solution.
The number of moles can be calculated as:
moles = mass / molar mass
where mass is the mass of Al(NO₃)₃ and molar mass is the molecular weight of Al(NO₃)₃
Substituting the given values, we get:
moles = 4.0 g / 213.0 g/mol = 0.01878 mol
The volume of the solution is given as 250 mL, which is equivalent to 0.25 L.
The normality of the solution is defined as the number of equivalents of solute per liter of solution. For Al(NO₃)₃, each mole of the compound produces 3 moles of ions, so the number of equivalents of Al(NO₃)₃ is:
equivalents = moles x 3
Substituting the value of moles, we get:
equivalents = 0.01878 mol x 3 = 0.05634 eq
The normality can now be calculated as:
normality = equivalents / volume
Substituting the given values, we get:
normality = 0.05634 eq / 0.25 L = 0.225 N
Therefore, the normality of the solution is 0.225 N.
The molarity of the solution is defined as the number of moles of solute per liter of solution. The number of moles of Al(NO₃)₃ in 250 mL of solution is the same as the number of moles in 1 L of solution, which is 0.01878 mol. Therefore, the molarity of the solution is:
molarity = moles / volume
Substituting the given values, we get:
molarity = 0.01878 mol / 0.25 L = 0.0751 M
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Enthalpy Lab + Questions NEED HELP ASAP FOR THE ANALYSIS QUESTIONS (be sure to show your work) + CONCLUSION
PURPOSE OF EXPERIMENT: To find Heat of Solution of sodium hydroxide and to find the heat of neutralization between sodium hydroxide and hydrochloric acid.
Experiment 1 Procedure:
1. Measure 50.0 mL of water (tap) into a 100 mL graduated cylinder and pour it into a large coffee cup.
2. Determine the temperature of this water
3. Measure out 2.00 g of sodium hydroxide into a piece of paper towel *tare scale!
4. Add the sodium hydroxide to the water in the coffee cup and put a small cup over it, with the thermometer through the hole. Stir GENTLY with the thermometer and record the temperature every 30 seconds for 3 minutes or until it peaks. Record this in a properly labelled table.
5. Let this stand for 45 minutes before proceeding to Exp. 2.
WHAT WE FOUND IN EXP 1:
T (temp.) initial = 20 degrees C
T (temp) FINAL = 28.5 degrees C
moles of sodium hydroxide = 0.0518mol
the molar mass of sodium hydroxide = 39.969g/mol
C (specific heat of water) = 4.184J/g degrees C
THE NUMBER OF TRIALS FOR TEMP IN EXP 1
1st trial = 21 C
2nd trial = 24.5 C
3rd trial = 26 C
4th trial = 26 C
5th trial = 28 C
6th trial = 28.5 C
7th trial = 28.5 C (final temp)
ANALYSIS FOR EXPERIMENT ONE:
1. Determine the moles of sodium hydroxide (NaOH) from the experiment.
2. Determine Qsurroundings and Qrxn
3. Determine the enthalpy for the dissociation of sodium hydroxide (delta H sol)
4. Write the thermochemical equation for the dissociation of sodium hydroxide TWO ways and write an enthalpy diagram
5. What assumptions did you make to calculate #2? (some example assumptions to make: assume that the solution is water and that heat and density COULD be the same as water, etc)
6. Research the actual value and determine the percent error
7. In terms of bonds breaking and forming, what is RESPONSIBLE FOR ENTHALPY CHANGE?
EXPERIMENT 2 PROCEDURE:
1. Measure out 50.0 mL of 0.75 concentration M HCl into a graduated cylinder
2. Measure and record the temperature of the sodium hydroxide solution from exp. 1.
3. Add the hydrochloric acid solution to the sodium hydroxide solution, put the small cup on, and record the temperature change every 15 seconds for 1 minute. Stir GENTLY. Record this in a properly labelled table (will be given below)
4. Solutions can be discarded down the sink.
WHAT WE FOUND IN EXP. 2:
T (temp) initial = 23.5 C
T (temp) FINAL = 27 C
THE NUMBER OF TRIALS FOR TEMP IN EXP 2
1st trial = 27 C
2nd trial = 27 C
3rd trial = 27 C
4th trial = 27 C (FINAL TEMP)
ANALYSIS FOR EXPERIMENT 2:
1. Determine the moles of HCl added to this mixture
2. Write the chemical equation for this reaction
3. Determine the limiting reagent
4. Determine the Qsurr and Qrxn *CONVERT TO kJ*
5. Determine the enthalpy for the neutralization reaction.
6. Write the thermochemical equation for the dissociation of sodium hydroxide TWO WAYS and write an enthalpy diagram
7. Research the actual value and determine the percent error.
8 Explain sources of experimental error for both experiments and BE SPECIFIC! (NOT CALCULATION ERRORS, SPILLING, OR LOSING REACTANTS - DO NOT COUNT AS ERRORS! They can be EXPERIMENTAL due to heat loss/gain, room temp *specific heat capacity is for 25 C*, and atmospheric pressure is constant. And they can be MEASUREMENTS - consider the precision and the potential range of error for each measurement)
9. In terms of bonds breaking and forming, what's responsible for the enthalpy change?
CONCLUSION: write a brief statement that refers to the purpose.
The difference between the energy needed to break the bonds in the reactants and the energy released when new bonds are created in the products is what essentially determines the enthalpy change.
What impact does bond breaking have on enthalpy?In general, a bond must be broken by a positive change in enthalpy, whereas a bond must be formed by a negative change in enthalpy. In other words, the process of breaking a bond is endothermic, whereas the process of forming a bond is exothermic.
What is the bond-breaking and bond-forming reaction's enthalpy change?The energy needed to break the links between the reactants less the energy released during the formation of new bonds in the products is the enthalpy of reaction.
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In terms of bonds breaking and forming, what's responsible for the enthalpy change?
Please help high to lowest
The order of the arrangement of the wavelengths from strongest to weakest is;
447 > 492 > 588 > 668
What is the wavelength?The wavelength is a fundamental property of a wave and is related to its frequency and speed through the equation:
wavelength = speed of light / frequency
where the speed of light is approximately 299,792,458 meters per second (m/s) and the frequency is measured in Hertz (Hz), which represents the number of cycles per second.
The wavelength is an important concept in many areas of physics, including optics, acoustics, and electromagnetic radiation.
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sample gas has a pressure of 6.8 kPa at 539K. If the temperature decreases to 211K, then what will be the new pressure?
Gay-Lussac's Law-
[tex] \:\:\:\:\:\:\star\longrightarrow \underline{\sf \boxed{\sf \dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}}}[/tex]
[tex] \:\:\:\:\:\:\star\longrightarrow \sf \underline{P_2=\dfrac{P_1 \:T_2}{T_1}}[/tex]
Where-
P₁ is the initial pressure.T₁ is the initial temperatureP₂ is the final pressure.T₂ is the final temperatureAs per question, we are given -
P₁ = 6.8 KPaT₁ =539 KT₂= 211KNow that we are given all the required values, so we can put them into the formula and solve for P₂:-
[tex] \:\:\:\:\:\:\:\:\:\:\:\:\longrightarrow \sf P_2=\dfrac{P_1 \:T_2}{T_1}\\[/tex]
[tex] \:\:\:\:\:\:\:\:\:\:\:\:\longrightarrow \sf P_2=\dfrac{6.8\times 211}{539}\\[/tex]
[tex]\:\:\:\:\:\: \:\:\:\:\:\:\longrightarrow \sf P_2 = \dfrac{1434.8}{539}\\[/tex]
[tex] \:\:\:\:\:\:\:\:\:\:\:\:\longrightarrow \sf P_2 = 2.661966.........\\[/tex]
[tex]\:\:\:\:\:\: \:\:\:\:\:\:\longrightarrow \sf\underline{ P_2 = 2.7 \:KPa}\\[/tex]
Therefore, If the temperature decreases to 211K, then the new pressure will become 2.7 KPa.
A certain first-order reaction ( A→products
) has a rate constant of 8.70×10−3 s−1
at 45 ∘C
. How many minutes does it take for the concentration of the reactant, [A]
, to drop to 6.25 %
of the original concentration?
Answer:
time = 1.92 min
Explanation:
By knowing that
[tex]R_R = K_R [A]^{1} = \frac{[A]}{time}[/tex]
Where: RR: rate of forward reaction, KR: rate constant, [A]: A concentration
in the previous equation, [A] is cancelled, then:
[tex]K_R = \frac{1}{time} \\ \\[/tex]
[tex]8.70\times10^{-3} = \frac{1}{time}[/tex]
Then, time = 114.94 seconds = 1.92 minutes
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Original Claims: In general, what types of substances tend to be acidic?
Fruit Juices
Beverages (Coffee/Soda/Milk)
Cleaning Products
Digestive Juices
Answer in this format.
Restate original Claim here. This claim was ______ (supported/ not supported) by the claim because ________.(give a brief description of the correct claim using terms pH, COLOR and pH PAPER)
For example, from the evidence,_____ (use THREE specific examples from your evidence of the pH value and color of the pH paper to support your answer)
Restate original Claim here. This claim was supported by the claim because the evidence showed that acidic substances have a pH value less than 7 and cause the pH paper to turn a certain color.
What is pH?
pH is a measure of the acidity or basicity of a solution. It is defined as the negative logarithm of the concentration of hydrogen ions (H+) in a solution. pH values range from 0 to 14, where 0 is the most acidic, 7 is neutral, and 14 is the most basic. A change of one unit in pH represents a tenfold change in the concentration of hydrogen ions.
For example, from the evidence, fruit juices such as lemon juice have a pH value of around 2-3 and turn the pH paper a red color, which indicates acidity. Beverages such as coffee and soda also have a low pH value, around 4-5, and turn the pH paper a slightly red color. Cleaning products such as vinegar have a pH value of around 2-3 and turn the pH paper a red color as well.
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using the balanced chemical reaction equations, and the energies of the reactants and products, calculate the combustion of glucose O2 = 498kj/1 mol o2, 1598kj/1mol H2O = 934kj/1mol H2O, use correct units
One mole of glucose burns to produce several gases. [tex]6600kJ[/tex] of power. Another way to put it is that the burning of glucose releases [tex]6600KJ/mol[/tex] thermal energy.
What's a straightforward explanation of combustion?A chemical reaction between two or more substances, typically containing oxygen, is called combustion. It results in the production of light and heat in the form of a flame.
The correct chemical formula for the burning of glucose
[tex]C6H12O6 + 6O2 \rightarrow 6CO2 + 6H2O[/tex]
We can determine the change in enthalpy for this reaction by using the values provided for the enthalpies of formation of the reactants and products:
Reactants:
[tex]C_6H_1_2O_6[/tex] : not given
[tex]O2: -498 kJ/mol \times 6 = -2988 kJ/mol[/tex]
Products:
[tex]CO_2[/tex]: not given
[tex]H2O -1598 kJ/mol \times 6 = -9588 kJ/mol[/tex]
[tex]\Delta H = (\epsilon products) - (\epsilon reactants)[/tex]
[tex]\Delta H = (-9588 kJ/mol + 0) - (0 + -2988 kJ/mol)[/tex]
[tex]\Delta H = -6600 kJ/mol[/tex]
Therefore, One mole of glucose burns to produce several gases. [tex]6600kJ[/tex] of power. Another way to put it is that the burning of glucose releases [tex]6600KJ/mol[/tex] thermal energy.
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Label each change as gradual or rapid:
Hurricane = ________
Volcanic eruption = ________
Regrowth after volcanic eruption = ________
Flooding = ________
Seasonal changes = ________
Oceans increasing temperature = ________
Global warming = ________
Fire = ________
Hurricane = Rapid
Volcanic eruption = Rapid
Regrowth after volcanic eruption = Gradual
Flooding = Rapid
Seasonal changes = Gradual
Oceans increasing temperature = Gradual
Global warming = Gradual
Fire = Rapid
Answer:
rapid
rapid
gradual
rapid
gradual
gradual
gradual
rapid
Explanation:
WORTH 50 POINTS, ANSWER ALL PARTS
For each of the following gemstones, determine the mass of compound present in the given moles of each compound.
PART A. The chemical formula for ruby is Al₂O₃. What is the mass in grams of ruby that are in 0.0924 moles?
PART B. The chemical formula for emerald is Be₃Al₂(SiO₃)₆. What is the mass in grams of emerald that are in 0.0165 moles?
PART C. The chemical formula for garnet is MgAl₂(SiO₄)₃. What is the mass in grams of garnet that are in 0.0380 moles?
Answer:
0.0924 mol Al₂O₃ = 9.42 g
0.0165 mol Be₃Al₂(SiO₃)₆ = 8.87 g
0.0380 mol MgAl₂(SiO₄)₃ = 13.5 g
Explanation:
mass = number of moles * molar mass
(PART A) The molar mass of Al₂O₃ is 101.96 g/mol. To find the mass in grams of Al₂O₃ that are in 0.0924 moles:
0.0924 mol * 101.96 g/mol = 9.42 g
(PART B) The molar mass of Be₃Al₂(SiO₃)₆ is 537.51 g/mol. To calculate the mass in grams of 0.0165 moles of Be₃Al₂(SiO₃)₆:
0.0165 mol * 537.51 g/mol = 8.87 g
(PART C) The molar mass of MgAl₂(SiO₄)₃ is 354.52 g/mol. To calculate the mass in grams of 0.0380 moles of MgAl₂(SiO₄)₃:
0.0380 mol * 354.52 g/mol = 13.5 g
The mass of ruby in grams is 9.43 g.
The mass of emerald in grams is 8.87 g.
The mass of garnet in grams is 16.56 g.
To calculate the mass of a compound in grams, we need to know the molar mass of the compound, which is the sum of the atomic masses of all the atoms in the formula. Once we know the molar mass, we can use the formula:
mass in grams = number of moles x molar mass
where the number of moles is given and the molar mass is calculated from the formula. In each case, we plug in the numbers and perform the calculation to obtain the mass in grams.
PART A: molar mass of Al₂O₃ is 101.96 g/mol (2 x 26.98 g/mol for Al and 3 x 16.00 g/mol for O).
As a result, the ruby mass in grammes is:
0.0924 moles x 101.96 g/mol = 9.43 g
PART B: The molar mass of Be₃Al₂(SiO₃)₆ is 537.54 g/mol (3 x 9.01 g/mol for Be, 2 x 26.98 g/mol for Al, 6 x 28.09 g/mol for SiO₃).
Therefore, The mass of an emerald in gram is :
0.0165 moles x 537.54 g/mol = 8.87 g
PART C: The molar mass of MgAl₂(SiO₄)₃ is 435.52 g/mol (1 x 24.31 g/mol for Mg, 2 x 26.98 g/mol for Al, 3 x 60.08 g/mol for SiO₄).
Therefore, the garnet mass in grams is :
0.0380 moles x 435.52 g/mol = 16.56 g
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Order the following elements from most to least reactive.
sodium, carbon, krýpton
sodium, krypton, carbon
krypton, sodium, carbon
carbon, sodium, krypton
It is the least reactive of the three elements listed. The correct order of elements from most to least reactive is:
sodium, carbon, krypton.
Sodium is a highly reactive metal and readily forms compounds with many other elements. It reacts vigorously with water and air, which is why it is stored in oil to prevent contact with moisture or oxygen.
Carbon is less reactive than sodium but can still undergo reactions, such as combustion or oxidation. Krypton, on the other hand, is a noble gas and is chemically inert, meaning it does not react with other elements under normal conditions. Therefore, it is the least reactive of the three elements listed.
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An unknown element contains 11 protons, 11 neutrons and 12 electrons, which of the following options do you think the unknown element is?
Answer:Sodium
Explanation:Sodium has 11 protons, 11 nuetrons, and 12 electrons
Calculate the volume of oxygen produced in the decomposition of 5 moles of KCIO3 at STP?
The volume of oxygen produced in the decomposition of 5 moles of KCIO3 at STP is 168 L. The balanced chemical equation for the decomposition of KCIO3 is:
2KClO3(s) → 2KCl(s) + 3O2(g)
From the equation, we can see that for every 2 moles of KCIO3, 3 moles of O2 are produced. Therefore, for 5 moles of KCIO3, the number of moles of O2 produced can be calculated as follows:
5 moles KCIO3 x (3 moles O2/2 moles KCIO3) = 7.5 moles O2
Since the conditions are given as STP (standard temperature and pressure), we can use the molar volume of a gas at STP (22.4 L/mol) to calculate the volume of O2 produced:
7.5 moles O2 x 22.4 L/mol = 168 L O2
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Consider the reaction. 2Pb(s)+O2(g)⟶2PbO(s) An excess of oxygen reacts with 451.4 g of lead, forming 338.4 g of lead(II) oxide. Calculate the percent yield of the reaction.
The reaction's per cent yield is 69.5%.
Calculation-We must compare the actual yield of the reaction to the theoretical yield of the reaction to get the per cent yield of the reaction.
First, we need to calculate the amount of Pb reacted using the given mass of Pb:
mass of Pb = 451.4 g
The molar mass of Pb is 207.2 g/mol, so the number of moles of Pb reacted is:
moles of Pb = mass of Pb / molar mass of Pb
moles of Pb = 451.4 g / 207.2 g/mol
moles of Pb = 2.179 mol
The theoretical yield of PbO can be calculated using the molar mass of PbO:
mass of PbO = moles of PbO × molar mass of PbO
mass of PbO = 2.179 mol × 223.2 g/mol
mass of PbO = 486.6 g
Therefore, the theoretical yield of PbO is 486.6 g.
The per cent yield of the reaction is:
per cent yield = (actual yield / theoretical yield) × 100%
per cent yield = (338.4 g / 486.6 g) × 100%
percent yield = 69.5%
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Will give 80 points pls help i need good grade plss need it fast
Introduction: The formation of the solar system has been a subject of scientific inquiry for centuries. One of the most significant forces at play in the formation of the solar system is the law of universal gravitation.
This law states that every object in the universe attracts every other object with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. In this virtual lab, we will investigate the law of universal gravitation by manipulating the size of the star and the positions of planets within Solar System X.
How to explain the informationHypothesis:
As the size of the star in Solar System X increases, the gravitational force experienced by the planets will increase, causing them to move closer to the star. Additionally, as the distance between the planets and the star decreases, the gravitational force experienced by the planets will also increase, causing them to move faster around the star.
Materials
Computer with internet connection
Virtual lab software
Solar System X simulation
Procedure:
Open the virtual lab software and access the Solar System X simulation.
Set the size of the star to the smallest setting and record the positions of the planets.
Increase the size of the star to the next setting and record the new positions of the planets.
Repeat step 3 until the largest size of the star is reached.
Analyze the data and record observations.
Results:
As the size of the star in Solar System X increased, the gravitational force experienced by the planets also increased. This caused the planets to move closer to the star and move faster around it. Additionally, as the distance between the planets and the star decreased, the gravitational force experienced by the planets also increased, causing them to move faster around the star. These observations support the hypothesis that the law of universal gravitation plays a significant role in the formation and movement of planets in a solar system.
Conclusion:
The law of universal gravitation is a fundamental force that plays a significant role in the formation and movement of planets in a solar system. This virtual lab demonstrated the effects of manipulating the size of the star and the positions of planets within Solar System X on the gravitational force experienced by the planets. The results of the experiment supported the hypothesis that increasing the size of the star and decreasing the distance between the planets and the star increased the gravitational force experienced by the planets, causing them to move faster and closer to the star. These observations provide valuable insight into the forces at play in the formation and movement of our own solar system and those found throughout the universe.
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name the process which takes place when a red litmus paper turns white when dropped into chlorine water
Explanation:
The process is called bleaching. Chlorine gas (Cl2) reacts with water to form hypochlorous acid (HOCl) and hydrochloric acid (HCl). Hypochlorous acid acts as a powerful oxidizing agent and removes electrons from the red litmus paper, causing it to turn white.
Need help with this please and thank you. PBS poisoned water student questions
When exposed to lead at high levels, the brain and central nervous system are attacked, resulting in unconsciousness, convulsions, and even death.
Future generations could be impacted by lead poisoning.Lead poisoning affects up to 800 million children worldwide, or close to one third of all children. Lead has a negative impact on a child's developing brain, leading to diminished IQ, behavioral difficulties, and learning issues that can lower potential earnings as an adult.
How much lead is permitted by law in US drinking water?The Safe Drinking Water Act (SDWA) reduced the maximum permitted lead level, or "lead-free" content, to a weighted average of 0.25 percent measured throughout the wetted surfaces of pipes, pipe fittings, plumbing fixtures, and fixtures, and 0.2 percent for solder and flux.
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What are the toxic effects of lead? How can it affect the human body?
you take a 25g chalk piece outside and draw for 5 min the chalk weighs 5g after how many molecules of chalk did you leave outside on the concreate. the chalk is CaCO3.
AnswerTherefore, you left approximately 1.202 x 10^23 molecules of CaCO3 on the concrete after drawing with a 25g chalk piece outside for 5 minutes.
Explanation:
To solve this problem, we need to use the concept of conservation of mass, which states that matter cannot be created or destroyed, only transformed from one form to another. Therefore, the total mass of the chalk before and after drawing must be equal.
The mass of the chalk before drawing is 25 g. After drawing for 5 minutes, the mass of the chalk is 5 g. Therefore, the mass of chalk that was used for drawing is:
25 g - 5 g = 20 g
Next, we need to convert the mass of the chalk used to the number of molecules. The molar mass of CaCO3 is 100.09 g/mol, which means that one mole of CaCO3 contains 6.022 x 10^23 molecules.
To calculate the number of molecules of chalk used for drawing, we can use the following steps:
Calculate the number of moles of CaCO3 used:
20 g / 100.09 g/mol = 0.1998 mol
Calculate the number of molecules of CaCO3 used:
0.1998 mol x 6.022 x 10^23 molecules/mol = 1.202 x 10^23 molecules
12. 50cm³ of alcohol is mixed with 50cm³ of water. The volume of the mixture is 97cm³. Which o the following is the best explanation for this observation red?
The alcohol and water molecules sharing the same space leads to a more compact arrangement of the molecules in the combination, which is the best explanation for the observed drop in volume.
When alcohol and water are combined, what happens to the volume?In this illustration, adding water to alcohol results in a final volume that is roughly 10% lower than the combined volumes of the two liquids. The "vanishing volume" results from variations in how the solvent molecules are packed in the mixture compared to the pure components.
Why does the volume drop when alcohol and water are combined?Alcohol molecules slide into the spaces between the water molecules as it dissolves, reducing the volume.
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If 50cm³ of alcohol is mixed with 50cm³ of water. The volume of the mixture is 97cm³. What is the best explanation for this observation?
A. Water evaporates leading to decrease in volume of the mixture
B. Water and alcohol molecules react and form a compact solution
C. Alcohol being volatile evaporates and decreases the volume of the mixture
D. The alcohol and water molecules sharing the same space leads to the decrease in volume of the mixture
Standard vinegar solutions are about 5% acetic acid by mass. What is the molarity of a 5% vinegar solution? The molar mass of acetic acid is 60.052 g/mol. The density of the solution is 1.01 g/mL.
Explanation:
To calculate the molarity of the vinegar solution, we first need to calculate the number of moles of acetic acid present in one liter of the solution.
Since the density of the solution is 1.01 g/mL, one liter of the solution will have a mass of 1.01 kg.
The mass of acetic acid in one liter of the solution can be calculated as follows:
mass of acetic acid = 5% × 1.01 kg = 0.0505 kg
The number of moles of acetic acid can be calculated using its molar mass:
moles of acetic acid = mass of acetic acid / molar mass of acetic acid
moles of acetic acid = 0.0505 kg / 60.052 g/mol
moles of acetic acid = 0.000841 mol
Therefore, the molarity of the vinegar solution is:
molarity = moles of acetic acid / volume of solution in liters
molarity = 0.000841 mol / 1 L
molarity = 0.000841 M
So, the molarity of a 5% vinegar solution is approximately 0.000841 M.
if you start with 2.196 g of salivic acid what is the theoretical yield of aspirin
forgot how to solve this
The value of the equilibrium constant, Kc is 0.33.
The correct option is A.
What is the value of the equilibrium constant, Kc?The balanced chemical equation for the oxidation of NO by O2 is:
2 NO (g) + O2 (g) → 2 NO2 (g)
From the stoichiometry of the equation, we see that the mole ratio of NO to O2 consumed is 2:1. Therefore, if 3 moles of O2 are present at equilibrium, then 1.5 moles of NO have been consumed:
1.5 moles NO = 15.0 moles NO (initial) - 3.0 moles NO2 - 3.0 moles O2
Using the law of mass action, we can express the equilibrium constant (Kc) for the reaction as:
Ke = ([NO2]^2 / [NO]^2 [O2])
We know that at equilibrium, [O2] = 3.0 moles / 1.0 L = 3.0 M. To calculate [NO2], we need to use the stoichiometry of the equation and the fact that 1.5 moles of NO are consumed at equilibrium:
2 mol NO → 2 mol NO2
1.5 mol NO → 1.5 mol NO2
Therefore, [NO2] = 1.5 mol NO2 / 1.0 L = 1.5 M. Substituting the values into the equilibrium constant expression, we get:
Ke = ([NO2]^2 / [NO]^2 [O2])
Ke = (1.5 M)^2 / (1.5 M)^2 (3.0 M)
Ke = 0.333
Therefore, the answer is (a) 0.33.
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what is the current produced y 120 volts passing through a resistance of 0.2 ohms?
Based on the amounts of starting materials used, a cheimst calculates a possible yield of 216.4 g in a reaction. However, after isolating her purified product, she finds that she has only 199.6 g of products. What is her percent yield for this reaction?
The chemist's percent yield for this reaction is approximately 92.27%.
What is percent yield?The percent yield for a chemical reaction is the ratio of the actual yield to the theoretical yield, expressed as a percentage. The theoretical yield is the amount of product that is expected to be obtained based on the stoichiometry of the reaction and the amounts of starting materials used. The actual yield is the amount of product that is actually obtained after the reaction is carried out and the product is purified.
Equation:To calculate the percent yield, we can use the formula:
Percent yield = (actual yield / theoretical yield) x 100%
In this case, the chemist calculated a theoretical yield of 216.4 g based on the amounts of starting materials used. However, she obtained an actual yield of 199.6 g after isolating and purifying the product.
So we can substitute these values into the formula and solve for the percent yield:
Percent yield = (199.6 g / 216.4 g) x 100%
Percent yield = 0.9227 x 100%
Percent yield = 92.27%
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How many milliliters (mL) of a 0.310 M NaOH solution are needed to neutralize 10.0 mL of 0.115 M H2SO4
10.0 mL of 0.115 M [tex]H_2SO_4[/tex] needs to be neutralised with 0.370 mL of a 0.310 M NaOH solution.
Calculate how much 0.310 M NaOH is required to neutralise 10.0 mL of 0.115 M [tex]H_2SO_4[/tex] in millilitres, we can apply the following formula:
Moles of [tex]H_2SO_4[/tex] = (Concentration of [tex]H_2SO_4[/tex])(Volume of [tex]H_2SO_4[/tex])
Moles of [tex]H_2SO_4[/tex] = (0.115 M)(10.0 mL) = 0.00115 moles
Since the reaction is 1 mole of [tex]H_2SO_4[/tex] to 2 moles of NaOH, we must have 0.00115 moles of NaOH to neutralize the [tex]H_2SO_4[/tex].
Moles of NaOH = (Concentration of NaOH)(Volume of NaOH)
0.00115 moles = (0.310 M)(Volume of NaOH)
Volume of NaOH =[tex]\frac{ 0.00115 moles}{0.310 M } = 0.370 mL[/tex]
Therefore, 0.370 mL of a 0.310 M NaOH solution are needed to neutralize 10.0 mL of 0.115 M [tex]H_2SO_4[/tex].
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Plants capture the sun's energy and make food in the process of photosynthesis. Only about 0.1 percent of the sun's energy is captured by plants. Plants take carbon dioxide and water and, using the energy from sunlight, convert it into glucose (food) and oxygen. About one-half of the energy absorbed by plants is used right away. The other half is stored in plants as energy-containing food (carbohydrates).
A green maple leaf with the chemical equation of photosynthesis below it, its reactants above and to the left and its products to the right of it.
A green maple leaf with the chemical equation of photosynthesis below it. The chemical equation has reactants of coefficient 6, CO subscript 2, +, coefficient 6, H subscript 2, 0, a yields arrow with the label light above it and chlorophyll below it, and products of coefficient 6 C subscript 6, H subscript 12, 0 subscript 6, + coefficient 6 0 subscript 2. Above the leaf is a down arrow pointing to the center of the left. To the left of this arrow is a rain cloud labeled water and to the right is a beaming sun labeled light. To the left of the lead is a grey cloud of gas labeled carbon dioxide with an arrow pointing toward the leaf. To the right of the lead are two parallel arrows the top of which points to the label glucose and the bottom to the label oxygen.
2. How do you think energy from the sun ends up in the crust, tomato sauce, cheese, and meat on a slice of pizza?
The food chain that produces elements like the crust, tomato sauce, cheese, and meat on a pizza begins with the energy that plants absorb from the sun through photosynthesis.
What is photosynthesis?Green plants, algae, and some microorganisms transform solar energy into chemical energy in the form of organic compounds like carbohydrates through a process called photosynthesis. Light energy is absorbed by pigments, chiefly chlorophyll, which is present in the chloroplasts of plant cells, during photosynthesis. Next, using this energy, glucose (a form of sugar) and oxygen are produced from carbon dioxide and water.
By photosynthesis, plants use the sun's energy to create carbohydrates (like glucose). Following the consumption of these carbohydrates by herbivores, predators subsequently consume these carbs, and so on.
When it comes to a pizza, the wheat used to form the crust was probably grown in a field where it employed photosynthesis to take in energy from the sun. Like with other vegetables used as toppings, the tomatoes used to prepare the sauce were probably also grown in a field. Pizza's cheese is formed from milk, which comes from cows who eat grass and other plants that have undergone photosynthesis to receive solar energy. Last but not least, any meat added as a garnish originated from creatures that also ate vegetables for fuel.
In a sense, the sun's energy, which plants use to produce food, including the components in a pizza, is eventually harnessed by photosynthesis.
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