Show:
Vocabulary
Moles to Moles
Mixed Problems
Mass to Mass
Miscellaneous
100
A conversion factor that relates the amounts in moles of any two substances involved in a chemical reaction.
What is mole ratio?
100

CO2 + 2LiOH --> Li2CO3 + H2O How many moles of water are made from 20 mol of CO2?

What is 20 mol H2O?

100

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?

100

What conversion factor is used to change from grams to moles or vice versa?

What is molar mass?

100

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%?

200
The measured amount of product obtained after performing a chemical reaction.
What is actual yield?
200

6CO2 +6H2O --> C6H12O6 + 6O2 

How many moles of oxygen are produced from 3.25 mol of water in the reaction described above?

What is 3.25 mol O2?

200

Mg + 2HCl --> MgCl2 + H2 

How many moles of MgCl2 will be made from 36.5g of HCl (MM=36.5 g/mol)?

What is 0.500 g MgCl2?

200

If two moles of copper (Cu) are found on a table, how many grams would that be?

What is 127.09 g of Cu?

200

Avogadro's number.

What is 6.022 x 10^23?

300
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.
What is the limiting reactant?
300

2Mg +O2 --> 2MgO How many moles of magnesium oxide are produced from 1.2 moles of magnesium?

What is 1.2 mol MgO?

300

Jeff completed a lab, producing 5.5 g of CaO2. If Jeff calculated he should produce 6.0g of CaO2, what is his percent yield?

What is 91.7%?

300

If 1 mole of sugar (C6H12O6) is placed on a scale, how many grams would that be?

What is 180.156 g C6H12O6?

300

How many moles are present in 34 grams of Cu(OH)2?

What is 0.35 mol Cu(OH)2?

400
The ratio of the actual yield to the theoretical yield, multiplied by 100.
What is percent yield?
400

Ammonia, NH3, is widely used as a fertilizer and in many household cleaners. Hydrogen (H2) can react with Nitrogen (N2) to make ammonia. What is the mole ratio between NH3 and H2?

What is 2/3 or 2 to 3?

400

Helen calculated she should make 320.0g of aspirin in her lab. When she completed the lab, she produced 340g of aspirin. What is her percent yield?

What is 106.3%?

400

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 310 g Na2SO4?

400

The reactant that is used up first in a chemical reaction.

What is limiting reactant?

500
States that mass is neither created nor destroyed during ordinary chemical or physical reactions. (This is why we balance chemical equations!)
What is the law of conservation of mass?
500

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?

500

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.

What is iron?

500

What is the molar mass of water?

What is 18.015 g/mol?

500

Write the complete balanced equation for the following reaction: When lithium hydroxide pellets are added to a solution of hydrogen sulfate, lithium sulfate and water are formed.

What is: 2LiOH + H2SO4 --> Li2SO4  + 2H2O