quiz review unit 6

1. Given the following equation: 2 KClO₃ ---> 2 KCl + 3 O₂

How many moles of O₂ can be produced by letting 12.00 moles of KClO₃ react at STP?

2. Given the following equation: 2 K + Cl₂ ---> 2 KCl

How many grams of KCl is produced from 2.50 g of K and excess Cl₂?

How many liters of Cl₂ are needed to produce 85.5 grams of KCl at STP?

3. Given the following equation: Na₂O + H₂O ---> 2 NaOH

How many grams of NaOH are produced from 1.20 x 10² grams of Na₂O?

How many moles of Na₂O are required to produce 1.60 x 10² grams of NaOH?

4. Given the following equation: 8 Fe + S₈ ---> 8 FeS

What mass of iron is needed to react with 16.0 grams of sulfur?

How many grams of FeS are produced?

5. Given the following equation: 2 NaClO₃ ---> 2 NaCl + 3 O₂

12.00 moles of NaClO₃ will produce how many liters of O₂?

How many grams of NaCl are produced when 8.75 liters of O₂ are also produced at STP?

Limiting Reagent (reactant)

6. How can you tell if it is a limiting reagent problem? What is a limiting reactant?

7. Hydrogen gas can be produced using the following reaction:

Mg + HCl à MgCl₂ + H₂

How many liters of hydrogen can be produced from 6.00 grams of HCl and 5.00 grams of Mg at STP?

8. Given the following equation: 8 Fe + S₈ ---> 8 FeS

How many grams of FeS will be produced when 10.0 grams of Fe reacts with 10.0 grams of S₈?

Which element is the limiting reactant? Which element is the excess reactant?

How many grams of the limiting reactant are left over?

How many grams of the excess reactant are left over?

9. Label the following as strong acid, weak acid, strong base, weak base, soluble salt, insoluble salt, element, molecular liquid, or molecular gas. Then ionize it, if appropriate.

a. NaClO₃ _________________ ____________________

b. HI _________________ ____________________

c. PbI₂ _________________ ____________________

d. NaOH _________________ ____________________

e. CCl₄ _________________ ____________________

f. O₂ _________________ ____________________

g. H₂O₂ _________________ ____________________

h. H₃PO₄ _________________ ____________________

i. Al(OH)₃ _________________ ____________________

j. Hg _________________ ____________________

k. BaSO₄ _________________ ____________________

l. HNO₃ _________________ ____________________

10. Complete the following by predicting the net ionic equations.

a. Solid lithium burns in air.

b. Magnesium metal is added to a solution copper (ii) nitrate.

c. Hydrochloric acid is added to solid sodium carbonate.

d. Sodium hydroxide solution is added to a solution of ammonium nitrate.

e. Ethanol (C₂H₅OH) is combusted.

f. Solutions of magnesium iodide and silver nitrate are mixed.

g. Chlorine gas is bubbled through a solution of sodium iodide.

h. Potassium metal is added to water.

i. Solid barium oxide is added to water.

j. Sodium metal is added to a solution of zinc nitrate.

Bonus: A confiscated white substance, suspected of being cocaine, was purified by a forensic chemist and subjected to elemental analysis. Combustion of a 50.86-mg sample yielded 150.0 mg CO₂ and 46.05 mg H₂O. Analysis for nitrogen showed that the compound contained 9.39% N by mass. The formula of cocaine is C₁₇H₂₁NO₄. Can the forensic chemist conclude that the suspected compound is cocaine?