Name __________________________________
Task Card 3:
Converting from Moles to Moles
*Mole Ratio: the coefficients in a chemical equation indicate the proportions in which substances react, in
moles or other counting units.
*Use coefficients to determine mole ratios.
The coefficients in a chemical equation indicate proportions in which different compounds react. Consider the
following BALANCED reaction equation:
CuSO4(aq) + 2NaOH(aq)  Cu(OH)2(s) + Na2SO4(aq)
The coefficients for each compound shown in the above reaction are listed below.
1 CuSO4
2 NaOH
1 Cu(OH)2
1 NaSO4
The coefficients in this reaction show that for every 1 mole of CuSO4, 2 moles of NaOH are required to cause
this reaction to successfully happen. The mole ratio between CuSO4 and NaOH is 1:2. Below is a list of other
mole ratios shown in the above balanced reaction.
CuSO4 and NaOH = 1mol CuSO4 : 2mol NaOH
CuSO4 and Cu(OH)2 = 1mol CuSO4 : 1mol Cu(OH)2
NaOH and Na2SO4 = 2mol NaOH : 1mol Na2SO4
To convert between moles of one compound to moles of another, you must use the mole ratio between the two
compounds.
Steps to Converting from Moles to Moles
Step 1: Identify the mole ratio between the two compounds in question
Step 2: Multiply the given number of moles by the mole ratio
*Tips: Make sure to correctly set up your mole ratio so the coefficient of the given is on the bottom!
Example:
If you react 5 moles of NaOH, how many moles of Na2SO4 will you produce?
CuSO4(aq) + 2NaOH(aq)  Cu(OH)2(s) + Na2SO4(aq)
Step 1: Identify the mole ratio between the two compounds in question
Na2SO4 and NaOH = 1mol Na2SO4 : 2mol NaOH
Step 2: Multiply the given number of moles by the mole ratio
5 mol NaOH x 1 mol Na2SO2/2 mol NaOH = 2.5 mol Na2SO4
Name __________________________________
1) Given this equation: N2 + 3H2 2NH3, write the following molar ratios:
a) N2 / H2
b) N2 / NH3
c) H2 / NH3
2) Given the following equation: 8H2 + S8  8H2S, write the following molar ratios:
a) H2 / H2S
b) H2 / S8
c) H2S / S8
Directions: Answer each of the following questions using the reaction equation provided.
3) 2NO + O2  2NO2
a. If you have 2 moles of NO how many moles of NO2 can you produce?
X _____________________
= _____________ mol NO2
b. If you have 4 moles of O2, how much NO will you need?
X _____________________
= _____________ mol NO
c. How much NO do you need to make 2.5 mol NO2?
X _____________________
4)
= _____________ mol NO
4NH3 + 3O2  4N2 + 6H2O
(Try this one without the boxes set up for you!)
a. 20 moles of NH3 are needed to produce how many moles of H2O?
b. How many moles of N2 will be produced if 3.5 moles of O2 are reacted?
Name __________________________________
5) Answer the following questions for this equation: 2H2 + O2  2H2O
a) What is the H2 / H2O molar ratio?
b) What is the O2 / H2O molar ratio?
c) Suppose you had 20 moles of H2, how many moles of H2O could you make?
d) Suppose you had 20 moles of O2, how many moles of H2O could you make?
6) Given the balanced chemical equation: Br2 + 2NaI  2NaBr + I2
How many moles of sodium bromide (NaBr) could be produced from 0.172 moles of bromine?
7) Given the equation, 8H2 + S8  8H2S:
a. How many moles of H2S can be formed from 12 mol H2?
b. How many moles of sulfur are needed to form 5 mol H2S?
c. How many moles of hydrogen are needed to completely react with 1.7mol sulfur?
8) Given the equation, Cu + 2AgNO3  Cu(NO3)2 + 2Ag:
d. How many moles of Cu are needed to react with 3.50 mol AgNO3?
e. If 6.25 moles of Ag are created, how many moles of copper were reacted?
f. If 5.12 mol Cu(NO3)2 are created, how many moles of silver were created?