Show:
Chemical Quantities
Stoichiometry
Formulas
100
What is the basic SI unit for measuring amount of a substance?
Moles
100
What is stoichiometry?
The calculation of quantities in chemical reactions.
100
What is the formula for finding the mass of an element or compound when given the amount of moles?
mass (grams) = number of moles x mass (grams)/ 1 mole
200
Give 3 examples of representative particles
Formula unit, molecule, atom
200
What is the mole ratio between HNO3 and NO2? 3NO2 + H2O ---> NO + 2HNO3
2:3
200
What is the molar volume of gas?
22.4 liters
300
What is the difference between empirical and molecular formula?
Empirical has lowest whole number ratio (simplified) while molecular formula shows the kinds and number of atoms in a compound molecule (not necessarily simplified)
300
How many moles of ammonia is formed when 0.60 moles of nitrogen reacts with hydrogen?
1.2 moles of NH3. 0.60 mol N2 x 2 mol NH3 / 1 mol N2 = 1.2 moles NH3
300
What is the formula for finding the percent composition?
% mass = mass of element in 1 mol compound/ molar mass of compound x 100%
400
How many representative particles are in a mole? How many liters in STP?
6.02 x 10^23 particles and 22.4 liters in 1 mole
400
How many molecules of oxygen are produced when 29.2 grams of water is decomposed by electrolysis according to this chemical equation? 2H20 (l) ---> 2H2 (g) + O2 (g)
29.2g H2O x 1 mol H2O/ 18.0g H2O x 1 mol O2/ 2 mol H20 x 6.02 X 10^23 O2/ 1 mol O2 = 4.88 X 10^23 molecules O2
400
What is the formula for percent yield?
percent yield = actual yield/ theoretical yield x 100%