Mass–mass calculations Transitional Reasoning Practice

Questions

1. 1.

   In a hydrometallurgical recycling facility, metallic copper is used to recover pure silver from an industrial silver nitrate solution according to the balanced equation $\text{Cu}(s) + 2\text{AgNO}_3(aq) \rightarrow \text{Cu(NO}_3)_2(aq) + 2\text{Ag}(s)$. A technician completely reacts exactly 190.65 g of pure copper wire with an excess of silver nitrate. Given the molar masses of $\text{Cu} = 63.55\text{ g/mol}$ and $\text{Ag} = 107.87\text{ g/mol}$, what theoretical mass of silver is precipitated?

   • A) 323.61 g
   • B) 647.22 g
   • C) 161.81 g
   • D) 381.30 g
2. 2.

   In an emergency oxygen generator, solid potassium chlorate decomposes upon heating according to the balanced equation $2\text{KClO}_3(s) \rightarrow 2\text{KCl}(s) + 3\text{O}_2(g)$. A technician tests a canister containing exactly 245.10 g of pure potassium chlorate. Given the molar masses of $\text{KClO}_3 = 122.55\text{ g/mol}$ and $\text{O}_2 = 32.00\text{ g/mol}$, what mass of oxygen gas is theoretically produced?

   • A) 96.00 g
   • B) 64.00 g
   • C) 48.00 g
   • D) 42.67 g
3. 3.

   In the industrial Kroll process used to manufacture aerospace-grade titanium, gaseous titanium(IV) chloride is reduced by molten magnesium according to the balanced equation $\text{TiCl}_4(g) + 2\text{Mg}(l) \rightarrow \text{Ti}(s) + 2\text{MgCl}_2(l)$. An engineering facility requires the production of exactly 143.61 g of solid titanium. Given the molar masses of $\text{Ti} = 47.87\text{ g/mol}$ and $\text{Mg} = 24.31\text{ g/mol}$, what minimum mass of magnesium metal is consumed in this reaction?

   • A) 145.86 g
   • B) 72.93 g
   • C) 36.47 g
   • D) 287.22 g
4. 4.

   In a spacecraft life-support system, carbon dioxide exhaled by astronauts is scrubbed from the cabin atmosphere using solid lithium hydroxide according to the balanced equation $2\text{LiOH}(s) + \text{CO}_2(g) \rightarrow \text{Li}_2\text{CO}_3(s) + \text{H}_2\text{O}(l)$. A specialized canister is scheduled to capture exactly 396.09 g of $\text{CO}_2$. Given the molar masses of $\text{LiOH} = 23.95\text{ g/mol}$ and $\text{CO}_2 = 44.01\text{ g/mol}$, what minimum mass of lithium hydroxide must the canister contain to completely react with this amount of carbon dioxide?

   • A) 431.10 g
   • B) 215.55 g
   • C) 107.78 g
   • D) 862.20 g
5. 5.

   In an industrial smelting operation, hematite ore containing iron(III) oxide is reduced by carbon monoxide according to the balanced equation $\text{Fe}_2\text{O}_3(s) + 3\text{CO}(g) \rightarrow 2\text{Fe}(s) + 3\text{CO}_2(g)$. A metallurgical chemist needs to isolate exactly 167.55 g of pure iron metal from this reaction. Given the molar masses of $\text{Fe} = 55.85\text{ g/mol}$ and $\text{Fe}_2\text{O}_3 = 159.70\text{ g/mol}$, what minimum mass of iron(III) oxide must react?

   • A) 239.55 g
   • B) 479.10 g
   • C) 119.78 g
   • D) 359.33 g

Answers and step-by-step solutions appear after you finish the test.