Vocabulary
A conversion factor that relates the amounts in moles of any two substances involved in a chemical reaction.
mole ratio
CO2 + 2LiOH --> Li2CO3 + H2O
How many moles of lithium hydroxide are required to react with 20 mol of CO2?
What is 40 mol LiOH?
Mg + 2HCl --> MgCl2 + H2 How many grams of hydrogen will be produced if we start with 2 moles of hydrochloric acid and excess magnesium?
What is 2 g H2?
Mg + 2HCl --> MgCl2 + H2
What mass of hydrogen is produced from the reaction of 75 g HCl (MM=36.5 g/mol) and excess Mg?
What is 2.0 g H2?
N2 + 3H2 --> 2NH3
In the reaction above, a student reacted 28 g of nitrogen with an excess of hydrogen. According to the students measurements, the reaction produced 30 g of product. The theoretical yield was 34 g. What is the student's percent yield?
What is 88%?
The measured amount of product obtained after performing an experiment.
actual yield
6CO2 +6H2O --> C6H12O6 + 6O2
How many moles of carbon dioxide are needed to react with 3.25 mol of water in the reaction described above?
What is 3.25 mol CO2?
Mg + 2HCl --> MgCl2 + H2
What mass of hydrochloric acid (MM=36.5 g/mol) is needed to react with 2.50 moles of magnesium?
What is 182 g HCl?
KClO3 --> 2KCl + 3O2
How many grams of KCl are produced if 5.0 g of KClO3 is decomposed?
What is 3 g KCl?
Avogadro's number
What is 6.022 x 1023?
The reactant that determines the amount of product (theoretical yield) that can form in a chemical reaction
limiting reactant
2Mg +O2 --> 2MgO How many moles of magnesium oxide are produced from 1.2 moles of magnesium?
What is 1.2 mol MgO?
How many moles of aluminum atoms are needed to combine with 1.58 mol of oxygen molecules to make aluminum oxide?
What is 2.1 mol Al?
Sodium and chlorine react to produce sodium chloride (table salt; MM=58.5 g/mol). Determine the amount of product that can be produced from 24.7 g of sodium and excess chlorine.
What is 62 g NaCl?
How many moles are present in 34 grams of Cu(OH)2?
What is 0.35 mol Cu(OH)2?
The ratio of the actual yield to the theoretical yield, multiplied by 100.
percent yield
Ammonia, NH3, is widely used as a fertilizer and in many household cleaners. How many moles of ammonia are produced when 6 mol of hydrogen gas react with an excess of nitrogen gas?
What is 4 mol NH3?
2Al + 6HBr → 2AlBr3 + 3H2
3.22 moles of Al reacts with 4.96 moles of HBr. What is the limiting reactant?
What is HBr?
Sodium hydroxide reacts with sulfuric acid (H2SO4; MM=98.1 g/mol) to form water and sodium sulfate. How many grams of sodium sulfate (MM=124 g/mol) will be formed from 200 g NaOH (MM=40 g/mol) and an excess of sulfuric acid?
What is 355 g Na2SO4?
Write the complete balanced equation for the following reaction: When lithium hydroxide pellets are added to a solution of sulfuric acid, lithium sulfate and water are formed.
What is: 2LiOH+ H2SO4 --> Li2SO4 + 2H2O
States that mass is neither created nor destroyed during ordinary chemical or physical reactions. (This is why we balance chemical equations!)
Law of Conservation of Mass
Hydrogen and oxygen gases react under a specific set of conditions to produce water. How many moles of oxygen would be required to produce 5.0 moles of water?
What is 2.5 mol O2?
2CuCl2 + 4KI → 2CuI + 4KCl + I2
When 0.56 moles of CuCl2 reacts with 0.64 moles of KI, how many moles of I2 are formed?
*Hint: find LR first!*
What is 0.16 mol I2?
When copper (II) chloride reacts with sodium nitrate, copper (II) nitrate and sodium chloride are formed. If 15 g CuCl2 (MM=134.5 g/mol) react with 20 g NaNO3 (MM=85 g/mol), how much sodium chloride (MM = 58.5 g/mol) can be formed?
What is 13.0 g NaCl?
This questions is worth 1000 points! SURPRISE! Chlorine gas reacts with potassium bromide to produce potassium chloride and bromine gas. How many grams of potassium chloride can be produced from 300.00 g each of chlorine and potassium bromide?
What is 188g of KCl?