Chemistry Unit 11

In a balanced chemical equation, the numbers of individual particles and the numbers of moles of particles are represented by the __.

coefficients

In a reaction, substances A and B form substance C. If the actual mole ratio of substance B to substance A is less than the balanced equation mole ratio of substance B to substance A, substance B is the __.

limiting reactant

Limiting a reactant is often accomplished by __.

using an excess of another reactant

What mass of SrF2 can be prepared from a reaction of 10.0 g Sr(OH)2 with excess HF? Sr(OH)2 + 2HF → SrF2 + 2H2O

10.3 g

Approximately how many grams of Fe2O3 are present in 0.82 mol Fe2O3?

130 g

What is the percent yield for the reaction between 9.8 grams of Ca(OH)2 and 9.8 grams of H3PO4 when 2.5 grams of Ca3(PO4)2 are actually obtained? 3Ca(OH)2 + 2H3PO4 → Ca3(PO4)2 + 6H2O

18%

Based on the following equation, how many moles of hydrochloric acid are needed to react with 0.64 moles of potassium permanganate? 2KMnO4 + 8HCl → 3Cl2 + 2MnO2 + 4H2O + 2KCl

2.6 mol HCl

Natural gas is mostly methane, CH4. When 128 grams of methane is burned in the chemical reaction shown below, how many grams of water vapor are produced? CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)

288 g

How many moles of CO2 would be produced from 56 moles of O2 according to the following balanced equation? 2C2H6 + 7O2 → 4CO2 + 6H2O

32 mol

How many moles of HCl will just react with 0.424 g Ba(OH)2? 2HCl + Ba(OH)2 → BaCl2 + 2H2O

4.94 x 10-3 mol

In the balanced chemical reaction shown below, what is the molar ratio of O2 to CO2? C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g)

5 : 3

In the decomposition reaction of compound AB into substances A and B, what is the number of mole ratios that can be formed?

6

What is the percent yield of CO2 if a reaction using 10.0 g CO with excess O2 produces 12.8 g CO2? 2CO + O2 → 2CO2

81.50 %

In the balanced chemical equation for the reaction between iron(III) oxide and aluminum, what is the molar ratio of Fe to Al? Fe2O3+2Al→2Fe+Al2O3

1 : 1

Which reactant in the following reaction is in excess when 9.8 grams of Ca(OH)2 is reacted with 9.8 grams of H3PO4? 3Ca(OH)2 + 2H3PO4 → Ca3(PO4)2 + 6H2O

H3PO4

In the chemical reaction below, 3.27 grams of Zn are reacted with 3.30 grams of HCl. Which component will limit the reaction? Zn + 2HCl → ZnCl2 + H2

HCl

Mole ratios for a reaction are obtained from the __.

balanced chemical equation