University:
Concordia University Wisconsin
Course:
CHEM 1414 | General Chemistry I
Academic year:

2022
Views:

199

Pages:

2
Author:

ilikemyicons0y5

More Stoichiometry with limiting and excess reactants 1. Lithium reacts with oxygen. a) Write the balanced equation. b) When 20.0 grams of lithium metal reacts with 30.0 grams of oxygen gas, which reagent is limiting and which is excess? c) How many grams of product are formed? d) How many grams of excess reagent remain unreacted? 2. Silver carbonate is an insoluble compound in water and forms according to the reaction: 2 AgNO3(aq) + K2CO3(aq) → a) How many grams of silver carbonate form, when 0.250 grams of potassium carbonate is mixed with 0.051 grams of silver nitrate? b) How many grams of excess reagent remain? 3. A common acid/base reaction is HCl(aq) + NaOH(aq) → a) If 0.150 grams of hydrochloric acid reacts with 0.150 grams of sodium hydroxide, how many grams of water will form? b) How many moles of excess reagent remain? 4. Sulfur is a fairly reactive chemical like its family member oxygen. It reacts with copper metal according to the reaction: 2 Cu(s) + S(s) → Cu2S(s). a) What is the mass of copper(I) sulfide formed if 100.0 grams of copper metal is mixed with 50.0 grams of sulfur? b) How many grams of excess reagent could you plan to recover from the reaction vessel? Answers: 1 a) 4Li + O2  2Li2O b) The limiting reagent is Li and the excess reagent is O2 c) 43.1 g of Li2O are formed d) 6.98 g of excess O2remain unreacted 2 2 AgNO3(aq) + K2CO3(aq) →2 Ag2CO3 (s) + KNO3 (aq) a) 0.0414 g of Ag2CO3 form b) 0.229 g of excess K2CO3remain 3 HCl(aq) + NaOH(aq) → HOH (aq) + NaCl (aq) a) 0.0676 g of water form b) 0.0131 g of excess HCl remain unreacted. 4 a) 125 g of Cu2S forms b) 24.9 g of excess (unreacted) Sulphur will be recovered from the reaction vessel. Note. Try this question again, but this time balance it using octatomic sulphur S8(s) as the reactant: Cu(s) + S8(s) → Cu2S(s). Explain why you get the same results as you did before, even though you are balancing it differently.