Molar Conversions
What is the molar mass of Al(OH3)3?
212.996 g/mol
What is percent composition?
identifies the mass percent of an element in the compound
What is the molecular formula of a compound with a molar mass of 180 g/mol and an empirical formula of CH₂O?
C6H12O6
If the balanced equation is 2 H₂ + O₂ → 2 H₂O, what is the mole ratio of hydrogen to water?
2 : 2
In the reaction 2 H₂ + O₂ → 2 H₂O, if you start with 3 moles of H₂ and 2 moles of O₂, which is the limiting reactant?
H2
How many moles are in 32 grams of oxygen gas (O₂)?
1 mol
Calculate the percent composition of carbon in CO₂.
27.29%
If a compound contains 40% carbon, 6.7% hydrogen, and 53.3% oxygen, what is its empirical formula?
CH₂O
What is the mole ratio between hydrogen and sodium in the reaction: 2Na + 2H2O → NaOH + H2?
1 : 2
N2+3H2→2NH3
You have 5.0 moles of N₂ and 12.0 moles of H₂. What is the limiting reactant?
H2
Convert 2.5 moles of sodium chloride (NaCl) to grams.
146.1 g
What is the formula for calculating percent composition?
% = (mass of element / mass of compound) x 100
Which compound is in its empirical form? C7H7, CF4, C6H12O6
CF4
What is a mole ratio?
a conversion factor between two substances in a chemical reaction, derived from the coefficients of a balanced chemical equation
What is a limiting reactant?
the substance in a chemical reaction that gets completely used up first, thereby determining the maximum amount of product that can be formed
If you have 18 grams of water (H₂O), how many moles do you have?
1 mol
If a compound has a molar mass of 58 g/mol and contains 24 g of oxygen, what is the percent composition of oxygen?
41.38%
What is the empirical formula of a compound?
An empirical formula represents the simplest whole-number ratio of atoms in a compound
N2+3H2→2NH3, If you have 6 moles of hydrogen gas (H₂), how many moles of ammonia (NH₃) can be produced?
4 mol
2Al+3Cl2→2AlCl3
Given 4.0 moles of Al and 4.0 moles of Cl₂: What is the limiting reactant?
Cl2
What is the amount of grams in 24 mol NaOH?
960 g
How is percent composition useful in determining empirical formulas?
it provides the mass ratios of elements in a compound, which can be converted to moles
A compound has a molar mass of 90g/mol and empirical formula of HCO2. What is the molecular formula?
C2H2O4
2Al+3Cl2→2AlCl3
How many moles of chlorine gas (Cl₂) are needed to completely react with 4 moles of aluminum (Al)?
6 mol
C3H8+5O2→3CO2+4H2O
A reaction uses 2.0 moles of propane (C₃H₈) and 8.0 moles of oxygen (O₂).
Identify the limiting reactant.
O2