Stoichiometry, Limiting Reagent, and Percent Yield
Random!
100
What is a mole?
A unit of measuring number of particles - 6.02 x 10^23 particles.
100
A compound found in gasoline has a mass of 35.8g. The sample contains 30.1g of carbon and 5.70 grams of hydrogen. What is the mass percent of hydrogen?
15.9%
100
What is the difference between an empirical and a molecular formula? Give an example of each.
empirical - lowest whole number ratio
molecular - tells you exact number of each atom in a molecule of the compound
100
Explain what the coefficient in a balanced chemical equation means.
Like a recipe, the coefficients are the ratio between each of the reactants and products in a chemical reaction.
100
Nitrogen and hydrogen is used to synthesize ammonia. Write a balanced chemical equation for the reaction.
N2 + 3H2 -> 2NH3
200
Determine the number of molecules in 1.2 moles of CH4.
7.2x10^23 molecules
200
Determine the percent composition of Cu2S.
% Cu = 79.9%
% S = 20.1%
200
Determine the empirical formula for a compound that is found by analysis to contain 27.37% sodium, 1.200% hydrogen, 14.30% carbon, and 57.14% oxygen.
NaHCO3
200
4Al(s) + 3O2(g) --> 2Al2O3(aq)
Determine the mass of oxygen required to oxidize 25 mol of aluminum.
600g
200
In a 10.0g sample of an orange compound, there is 2.7g of potassium, 3.5g of chromium, and 3.8g of oxygen. Determine the percent composition.
27% K, 35% Cr, 38% O
300
Determine the molar mass of Al2(SO4)3.
342.17g/mol
300
Determine the mass percent of water for the hydrate SrS2O3*4H2O
26.5%
300
Determine the empirical formula for a compound that contains 69.88g of iron and 30.12g of oxygen.
Fe2O3
300
Determine the limiting reactant when 1.00g of CaF2 reacts with 15.5g of H2SO4.
CaF2(S) + H2SO4(aq) --> HF(g) + CaSO4(s)
CaF2
300
A 56.4g sample of a compound with a molecular molar mass of 210g/mol was found to be composed of 12.35g of sodium, 25.77g of carbon, 1.07g of hydrogen and an unknown mass of oxygen. What is the molecular formula for this compound?
Na2C8H4O4
400
Determine the number of Br atoms in 2.32 mol of FeBr3
4.15x10^24 atoms of Br
400
Determine the composition of strontium nitrate
Sr - 41.40%, N-13.24%, O- 45.36%
400
A 3.34g sample of a hydrate SrS2O3*xH2O(s), contains 2.30g of SrS2O3(s). Find the value of x.
5
400
In the equation below, determine the moles of iron (III) nitrate that forms if 18.00g of silver nitrate is mixed with 32.4g of iron (III) chloride.
AgNO3 + FeCl3 -> AgCl + Fe(NO3)3
AgNO3 is limiting
0.03532mol
400
KI is reacted with AgNO3 in a double displacement reaction. If there are 498.0 g of potassium iodide added to 339.8 g of silver nitrate, what is the mass of each product?
496.6 g AgI, 202.2g KNO3
500
Determine the number of atoms of oxygen in 3.21g of aluminum hydroxide.
7.43x10^22 atom of oxygen
500
What mass of silver is contained in 200kg of silver nitrate, AgNO3(s)?
127kg
500
An unknown compound contains 42.6% oxygen, 32% carbon, 18.7% nitrogen, and the remainder hydrogen. Using mass spectrometry, its molar mass was determined to be 75.0g/mol. What is the molecular formula for the compound?
C2H5NO2(s)
500
Consider the following reaction:
C6H12O6(aq) --> 2C2H5OH(aq) + 2CO2(g)
If 20.0g of glucose reacts but only 1.40g of ethanol is produced, what is the percent yield of the reaction?
13.7%
500
Consider the following reaction:
CaCO3 + FePO4 --> Ca3(PO4)2 + Fe2(CO3)3
Assuming we start with 100. grams of calcium carbonate and 45.0 grams of iron (III) phosphate, what mass of the excess reactant(s) is left over?