CHAPTER 9 REVIEW

IB Chem I Worksheet- Topic 1 Stoichiometry

Name: ___________________________________________ Date:_________

Warm-up: Write a balanced chemical equation below for the reaction of solid magnesium metal with aqueous hydrochloric acid (HCl) in a single replacement reaction. Remember to include state symbols.

1. 0.15g Mg, 0.30g Mg, 0.60g, and 1.20g Mg are all reacted with the same amount of hydrochloric acid (0.050mol HCl). For each different mass, find if the magnesium or HCl was the limiting reactant, and how much of the excess reactant was leftover, if any. Show all your work below and circle your final answer.

2. Given the following equation: C3H4(g) + xO2(g) 3CO2(g) + 2H2O(g)

a.What is the value of the coefficient x in this equation?

b.What is the molar mass of C3H4?

c.What is the mole ratio of O2 to H2O in the above equation?

d.How many moles are in an 8.0 g sample of C3H4?

e.If z mol of C3H4 react, how many moles of CO2 are produced, in terms of z?

3.Are actual yields typically larger or smaller than theoretical yields?

PROBLEMS: Show all your work in the space provided.

4.Write a balanced chemical equation below for the synthesis reaction of gaseous nitrogen with gaseous hydrogen. Assume the reaction represented by the following equation goes all the way to completion:

a. If 6 mol of H2 are consumed, how many moles of NH3 are produced?

b. How many grams are in a sample of NH3 that contains 3.0 1023 molecules?

c.If 0.1 mol of N2 combine with H2, what must be true about the quantity of H2 for N2 to be the limiting reactant?

5.If a reaction’s theoretical yield is 8.0 g and the actual yield is 6.0 g, what is the percentage yield (%yield = (actual yield/theoretical yield)*100?

6.Joseph Priestley generated oxygen gas by strongly heating solid mercury(II) oxide in a decomposition reaction, breaking it apart into its component elements. Write a balanced chemical equation for this reaction below:

a. If 15.0 g HgO decompose, how many moles of HgO does this represent?

b. How many moles of O2 are theoretically produced from the 15.0g?

c. How many grams of O2 is this?

d. If the percentage yield is 95.0%, how many grams of O2 are actually collected?

READ p. 28-32 and complete exercises #36-44. Remember to show all of your work, use significant figures, and write balanced chemical equations with state symbols when applicable for full credit.