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?
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?
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?
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?
88%
The measured amount of product obtained after performing a chemical reaction.
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?
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?
182 g HCl
2KClO3 --> 2KCl + 3O2 How many grams of KCl are produced if 5.0 g of KClO3 is decomposed?
3 g KCl
Avogadro's number.
6.022 x 1023
The reactant that determines the amounts of the other reactants that can combine--and the amount of product that can form--in a chemical reaction.
the limiting reactant
2Mg +O2 --> 2MgO How many moles of magnesium oxide are produced from 1.2 moles of magnesium?
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?
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.
62 g NaCl
How many moles are present in 34 grams of Cu(OH)2?
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?
4 mol NH3
Ammonia decomposes to produce nitrogen and hydrogen gases. How many moles of H2 can be formed by the decomposition of 0.145 moles of ammonia?
0.218 mol H2
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?
355 g Na2SO4
Write the complete balanced equation for the following reaction (include states): When lithium hydroxide pellets are added to a solution of sulfuric acid, lithium sulfate and water are formed.
2LiOH (s) + H2SO4 (aq) --> Li2SO4 (aq) + 2H2O (l)
What is the name of the lawa that states that mass is neither created nor destroyed during ordinary chemical or physical reactions. (This is why we balance chemical equations!)
the 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?
2.5 mol O2
Aluminum oxide reacts with iron to form Fe3O4 and Aluminum. Determine with limiting reactant when 5 moles of aluminum oxide reacts with 7 moles of iron.
iron
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?
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. g each of chlorine and potassium bromide?
188 g KCl