STOICHIOMETRY
REVIEW
(pick a partner)
When 1.25 g of a rock (containing CaCO3 and other inert materials) is dissolved in acid, 0.44 g CO2 was generated. What is the % CaCO3 in the rock?
80%
What is the empirical formula of a hydrocarbon (CxHy) that is 10% hydrogen by mass?
C3H4
How many grams of calcium nitrate contain 24 g of oxygen atoms?
41 g
What mass of copper would be produced if 0.10 moles of copper(I) oxide is reacted with hydrogen to form copper metal?
13 g Cu
When 0.60 moles of carbon disulfide reacts with 1.5 moles of oxygen to make CO2 and SO2, how many moles of CO2 are made?
0.5 mol CO2
When CH4 undergoes combustion, 72 g of water form. How many g of CH4 reacted?
32 g CH4
What’s the empirical formula of a compound containing 26 g of chromium and 12 g of oxygen?
Cr2O3
If bromine’s atomic mass is ~80 amu, and there are only two naturally occurring isotopes: 79Br and 81Br, what is the % of 79Br in natural Br?
50%
How many grams of chromium are in 98 g of potassium dichromate?
35 g Cr
How many molecules of sucrose are in 684 g of sucrose, C12H22O11?
1.20 x 1024 molecules
How many carbon atoms are in 360 g of glucose, C6H12O6?
7.2 x 1024 atoms
How many moles of O2 are required to oxidize 1.0 moles of C3H6O2 to produce CO2 and water?
3.5 moles
A compound contains 32 g of sulfur and 76 g of fluorine. What is the empirical formula?
SF4
Iron(II) hydroxide reacts with oxygen gas and water to form iron(III) hydroxide. How many moles of iron(III) hydroxide will form for every 1 mole of oxygen gas used?
4 mol
If 0.40 mol H2 and 0.15 mol of O2 react to form water. What mass of which reactant is left over after the reaction has gone to completion?
0.20 g H2 remains
When C8H18 undergoes complete combustion, what is the mole-to-mole ratio of C8H18 to O2?
2 mol C8H18 : 25 mol O2
How many moles of O2 are needed to produce 56.8 g of P4O10 from phosphorus and oxygen?
1.00 mol
How many grams of sulfuric acid contain 32 g of oxygen atoms?
49 g
Unknown element X combines with oxygen to form compound XO2. If 44.0 g of X combine with 8.00 g of oxygen, what is the atomic mass of X?
176 amu
When 0.600 moles of BaCl2 react with 0.250 moles of K3AsO4, what is the maximum number of moles of Ba3(AsO4)2 that could be formed?
0.125 mol
A bottle of rubbing alcohol contains 90.% C3H8O by mass. How many grams of rubbing alcohol contain 9.0 g of C3H8O?
10. g
What mass of copper is produced when 0.05 moles of copper(II) oxide is reacted with excess H2 to form copper metal ?
3 g Cu
What is the average atomic mass of element X if naturally occurring X contains 20% 100X, 50% 102X and 30% 105X?
102.5
If 28 g of an alkene (C2H2n) is burned in excess oxygen, how many grams of H2O are formed?
36 g H2O
Tungsten metal may be prepared by reducing WO3 with H2 gas. How many grams of tungsten may be prepared from 0.05 mol WO3 and excess H2?
9 g
How many grams of nitrogen are in 66 g of ammonium sulfate?
14 g
What is the empirical formula of a nitrogen oxide if it contains 64% nitrogen by mass?
N2O
How many moles of oxygen gas will form when 221 g of gold(III) oxide decomposes?
0.750 mol
What is the SUM of the coefficients when the reaction below is balanced?
___C4H11N + ___O2 → ___CO2 + ___H2O + ___N2
4 27 16 22 2
71
How many moles of MnSO4 are produced when 1.0 mol KMnO4, 5.0 mol H2C2O4, and 3.0 mol H2SO4 are mixed according to:
2KMnO4 + 5H2C2O4 + 3H2SO4 →
K2SO4 + 2MnSO4 + 10CO2 + 8H2O
1.0 mol
How many moles of O2 are produced from 4.0 mol potassium chlorate in the following equation?
___KClO3 → ___KCl + ___O2
6.0 mol
2 2 3
How many moles of O2 will react with 1.00 mol C8H18 in the following reaction?
___C8H18 + ___O2 → ___CO2 + ___H2O
12.5 mol
2 25 16 18
A solution containing 0.20 mol KBr and 0.20 mol MgBr2 in 2.0 L of water is available. How many mol lead(II) nitrate must be added to precipitate all of the bromide as insoluble PbBr2?
0.30 mol
An acid contains 40.0% C and 6.71% H. The remainder is oxygen. What is the empirical formula of the acid?
H2CO