Mole to Mole
If 2 moles of H2 react with O2 to form water according to the equation 2H2+O2→2H2O, how many moles of H2O are produced?
2 moles of H2O
What is the molar mass of CaCO3 (to two decimal places)?
100.09 g/mol
What volume (in liters) does 1.00 mole of an ideal gas occupy at STP (standard: 22.4 L/mol)?
22.4 L
How many particles are in 2.00 moles of helium atoms? (Use Avogadro's number 6.022×10^23)
1.20×10^24 atoms
What is the percent composition by mass of oxygen in H2O? (Use MM H2O=18.02 g/mol)
88.8% O
For the reaction 2KClO3→2KCl+3O2, how many moles of O2 form from 4.0 moles of KClO3?
6.0 moles O2.
How many moles are in 25.0 g of NaCl?
0.428 mol.
How many liters at STP are occupied by 0.350 moles of CO2?
7.84 L
How many atoms are in 12.0 g of carbon (C)? (Use MM C=12.01 g/mol and Avogadro's number 6.02×10^23)
6.02×10^23 atoms
Determine the percent composition (by mass) of carbon in C2H5OH (ethanol). (Use MM C2H5OH=46.07 g/mol)
52.2% C
Given 2Al+3Cl2→2AlCl3, if 0.75 moles of Al react completely, how many moles of Cl2 are required?
(three decimal places)
1.125 moles Cl2.
Using 2H2+O2→2H2O, how many grams of H2O can be produced from 4.0 g of H2? (Use MM of H2=2.02 g/mol, H2O=18.02 g/mol.)
35.7 g H2O
What volume (L at STP) is produced by the decomposition of 5.00 g of KClO3 that yields O2 per the equation 2KClO3→2KCl+3O2? (Use MM KClO3=122.55 g/mol, assume STP: 22.4 L/mol.)
1.37 L O2
How many molecules are in 18.0 g of H2O? (Use MM H2O=18.02 g/mol)
6.01×10^23 molecules
A reaction’s stoichiometry predicts 0.500 mole product (molar mass = 58.44 g/mol) as theoretical yield. If the student isolates 24.0 g, calculate percent yield.
82.1%.
For 2H2+O2→2H2O, if you have 2.0 moles of H2 and 0.6 moles of O2, which is limiting and how many moles of H2O form? (Two Answers)
O2 limiting; 1.20 moles H2O
Calculate the molar mass of C6H12O6 (glucose).
180.16 g/mol
Given 2H2+O2→2H2O, if 2.24 L of H2 (STP) react with excess O2, how many liters of H2O vapor (assume gas) would form at STP?
2.24 L H2O (gas).
How many oxygen atoms are in 0.250 mol of Al2(SO4)3?
1.81×10^24 oxygen atoms
In a reaction, the limiting reagent calculation gives a theoretical yield of 12.0 g. If only 9.00 g are recovered, what is the percent yield?
75.0%
For the reaction N2 + 3 H2 → 2 NH3, if 5.0 moles of H2 are available, which reactant limits ammonia production and how many moles of NH3 are produced assuming excess N2? (Assume only H2 amount given.)
(Two Answers)
Limiting reagent: H2,
NH3 produced = 3.33 mol
For the reaction N2+3H2→2NH3, if you have 14.0 g of N2 and 6.0 g of H2, which reagent limits and how many grams of NH3 can form? (Use MM N2=28.02 g/mol, MM H2=2.02 g/mol, MM NH3=17.03 g/mol)
(Two Answers)
N2 limits; 17.0 g NH3.
A sample of gas collected at STP contains 2.24 L of O2 and 4.48 L of N2. What are the mole amounts of each gas, and what is the total moles of gas collected?
(Three Answers)
O2 = 0.100 mol
N2 = 0.200 mol
Total = 0.300 mol
A 3.00 g sample of NH4NO3 contains how many nitrogen atoms? (Use MM NH4NO3=80.04 g/mol; count N atoms per formula unit.)
4.51×10^22 N atoms
A compound has empirical formula CH2 and a molar mass of approximately 84. What is its molecular formula?
C6H12