Chemistry Honors ­ Quantitative Study of a Reaction Lab Analysis
Directions: Using your laboratory data and observations, complete the questions below with your lab partner. You may not use any other resources, or speak with any other lab groups. For calculations, show all work and units, follow sig fig rules, and use dimensional analysis when appropriate.
1. Write a skeleton (unbalanced) equation for the reaction that took place in this lab. Assume copper forms a +2 ion during the reaction. Include states of matter. Do not balance the equation.
2. Match the chemical identities of the two products with their locations below.
Dried filtrate: ________________________
Dried substance in filter paper ___________
3. Calculate the change in mass of the copper wire. This mass of copper that you calculate, is the mass of copper that reacted in this lab. 4. Convert this mass of copper that reacted to moles.
5. A chemistry student argues that the lab results violate the law of matter conservation, since the copper wire lost mass, and therefore these copper atoms disappeared. In a single sentence, explain why this student is wrong, and needs to pay attention more in class!
6. Calculate the mass of silver nitrate that was used in this lab.
7. Convert this mass of silver nitrate to moles.
8. Calculate the mass of elemental silver that was produced.
9. Convert this mass of silver to moles.
10. Calculate the mass of the copper compound produced. 11. Calculate the following ratios. Write your answer in fractional form with units. Use example as a guide. Example: 0.740 mol Mg = 2.17 mol Mg (Keep units on both numerator and denominator!)
0.341 mol Al 1 mol Al
(a) moles silver produced = (b) moles silver produced__ = moles copper reacted moles silver nitrate reacted
12. Rewrite the skeleton equation for this lab reaction below, leaving room for coefficients. Now, balance this equation using the experimental mole ratios from the calculations you just performed in question #11. Round the numerators in your ratios to whole numbers before using them. Even if the mole ratios do not balance the equation correctly, use them anyhow, and then say
what the calculated ratios should have been. 13. The purpose of this lab was to examine the relationship between the masses of chemicals in a reaction, and the coefficients in a balanced chemical equation. Write a conclusion statement, explaining what you learned about the connection between masses and coefficients.
14. Did your lab data support the law of mass conservation? Show a calculation to support
your answer. Chemistry Honors ­ Quantitative Study of a Reaction Names: ___________________________
Percent Error Calculations
/ 10 points ___________________________
___________________________
Directions: Calculate the percent error in your mole ratios and masses. Show calculation work.
1. Write the formula for percent error below. When you apply it in the calculations, you do not have to re­write it again.
2. If the true value for the mol Ag : mol Cu ratio is 2.00, calculate your percent error.
3. If the true value for the mol Ag : mol AgNO3 ratio is 1.00, calculate your percent error.
4. What was your calculated difference in mass between the reactants and products – your answer to #14? What should it have been? Chemistry Honors ­ Quantitative Study of a Reaction
Lab Analysis
Names: ___________________________
/ 28 points ___________________________
___________________________
Quantitative Study of a Reaction Lab Analysis Answer Sheet
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2. Dried filtrate: ________________________
Dried substance in filter paper ___________
3. 4.
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6. 7. 8.
9. 10. 11. (a)
11. (b)
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14.