The Mole and Particles
State the value of the Avogadro constant including its units.
6.022 x 10^23 mol^-1
What is molar mass?
The sum of all the relative atomic masses of all the atoms in a molecular formula.
What information do the stoichiometric coefficients in a balanced equation give?
The mole ratio of reactants and products.
State the molar volume of an ideal gas at STP in dm^3.
22.7 dm^3 mol^-1
What is the difference between an empirical and molecular formula?
Empirical is the simplest ratio; molecular is the actual number of atoms.
Find the number of moles of atoms in 3.01 x 10^23 atoms of copper.
0.500 mol
Calculate the molar mass of magnesium nitrate, Mg(NO3)2.
148.33 g mol^-1
For N2 + 3H2 -> 2NH3, how many moles of NH3 form from 4.0 mol of H2?
2.67
What volume does 0.500 mol of CO2 occupy at STP?
11.4 dm^3
What is the term for a solution of accurately known concentration?
Standard solution
Calculate the total number of hydrogen atoms in 0.200 mol of (NH4)2SO4.
4.82 x 10^23 atoms
Find the percentage by mass of oxygen in CuSO4 * 5H2O.
57.67%
What mass of water forms when 4.00 g of H2 burns in excess O2 (2H2 + O2 -> 2H2O)?
35.7g
Calculate the moles in 45.4 dm^3 of oxygen gas at STP.
2.00 mol
Define a limiting reactant in a chemical reaction.
The reactant that is completely consumed and limits the amount of product formed
What mass of CO2 has the same number of molecules as 2.00 g of helium gas?
22.0g
A compound has empirical formula CH2 and molar mass 70.1 g mol^-1. Find its molecular formula.
C5H10
If 10.0 g of CaCO3 decomposes to give 4.50 g of CO2, what is the percentage yield?
102%
Find the density of methane gas (CH4) at STP in g dm^-3.
0.705g dm^3
Why do real gases deviate from ideal behavior at high pressures and low temperatures?
Particles have finite volume and intermolecular forces become significant
A hydrocarbon sample has 3.01 x 10^22 molecules and weighs 1.40 g. Find its molar mass.
28.0 g mol^-1
Find the empirical formula of an iron oxide that is 72.4% Fe and 27.6% O by mass.
Fe3O4
For 2Al + 3Cl2 -> 2AlCl3, 5.40 g Al mixes with 14.2 g Cl2. What is the limiting reagent?
Chlorine(Cl2)
A fixed gas mass occupies 200 cm^3 at 27 degrees C. At constant pressure, what temp makes it 400 cm^3?
600 k
What term describes a reaction where heat is released to the surroundings?
Exothermic Reaction