Stoichiometry Review

Molar Conversions

100

If I have a mole of skittles, how many skittles do I have?

6.02 x 10²³ skittles 

200

If I have 1 mole of Zinc, how many grams of Zinc do I have? 

65.38 grams 

300

If I have 80. grams of Calcium, how many moles of Calcium do I have? 

2.0 moles

400

If I have 2.0 moles of Sodium Chloride (NaCl), how many grams of sodium chloride do I have? 

120 grams 

500

If I have 25 grams of LiCl, how many molecules of LiCl do I have? 

3.6 x 10²³ molecules LiCl

Balancing/Types of Reactions

100

Why do we need to balance chemical reactions? (what is that law called?)

The Law of Conservation of Matter 

"matter can neither be created nor destroyed"

200

What type of reaction is this?

Zn + 2HCl ==> ZnCl₂ + H₂

Single Replacement

300

Balance the following:

__ Na + ___ Cl₂ ==> ___ NaCl

2 Na + 1 Cl₂ ==> 2 NaCl

400

Balance the following: 

___ Al₂O₃ ==> __ Al + __ O₂

__2_ Al₂O₃ ==> _4_ Al + _3_ O₂

500

Balance and tell me the type of reaction for the following: 

Pb(NO₃)₂ + NaI ==> NaNO₃ + PbI₂

Pb(NO₃)₂ + 2 NaI ==> 2 NaNO₃ + PbI₂

Double Replacement

Moles A to Moles B

100

2 NaCl ==> 2 Na + Cl₂

According to the above reaction, what are the two possible molar ratios comparing Sodium (Na) and Chlorine (Cl₂)?

2 mol Na / 1 mol Cl₂

1 mol Cl₂ / 2 mol Na 

200

2 Fe₂O₃ ==> 4 Fe + 3 O₂

What are the 6 possible molar ratios for the above reaction? 

2 mol Fe₂O₃ / 4 mol Fe

4 mol Fe / 2 mol Fe₂O₃

2 mol Fe₂O₃ / 3 mol O₂

3 mol O₂ / 2 mol Fe₂O₃

4 mol Fe / 3 mol O₂

3 mol O₂ / 4 mol Fe

300

2 NaCl ==> 2 Na + Cl₂

If I decompose 4.0 moles of NaCl, how many moles of Cl₂ do I form? 

2.0 moles Cl₂

400

Using the following, determine how many moles of Na₂O are formed if I react 2.0 moles of Na with excess O₂.

4 Na + 1 O₂ → 2 Na₂O

1.0 mol Na₂O

500

___ C₃H₈ + ___ O₂ → ___ CO₂ + ___ H₂O

Balance the above reaction. If I react 6.0 moles of C₃H₈ with excess O_2, how many moles of CO₂ do I make?

18 moles of CO₂

Grams A to Moles B or Moles A to Grams B

100

How many steps do you use to convert from grams of one substance in a reaction to moles of another? 

2 steps (molar mass and then molar ratio)

200

4 Na + 1 O₂ → 2 Na₂O

If I react 32 grams of O₂ with excess Na, how many moles of Na₂O are formed?

2.0 moles Na₂O

300

2 NaCl ==> 2 Na + Cl₂

If I react 4.0 moles of NaCl, how many grams of Cl₂ are formed?

140 grams Cl₂

400

__ NaCl ==> __ Na + __ Cl₂

If I decompose 29 grams of NaCl, how many moles of Cl₂ are formed? 

0.25 moles Cl₂

500

___ NaCl+ ___ F₂ → ____ NaF + ___ Cl₂

If I react 19 grams of Fluorine (F₂) with excess Sodium Chloride, how many moles of Sodium Fluoride (NaF) do I make? 

1.0 moles NaF

Grams A to Grams B

100

How many steps do you use to convert from grams of one substance to grams of a different substance in a reaction? 

3 steps (molar mass of original substance, molar ratio, molar mass of new substance) 

200

4 Na + 1 O₂ → 2 Na₂O

Using the above BALANCED reaction, if I react 23 grams of Na, how many grams of O₂ do I need? 

31 grams Na₂O

300

Na₃PO₄ + 3 KOH → 3 NaOH + K₃PO₄

Using this BALANCED reaction, if I react 19 grams of Potassium Hydroxide (KOH), how many grams of Potassium Phosphate (K₃PO₄) are formed? 

24 grams of K₃PO₄

400

___ Al₂O₃ ==> __ Al + __ O₂

Using the above reaction, if I produce 54.0 grams of Al, how many grams of Al₂O₃ do I decompose? 

102 grams Al₂O₂

500

___ Al  + __ Fe₃N₂  →  ___ AlN + __ Fe

Using the UNBALANCED reaction.

If I react 27 grams of Aluminum (Al) with excess Iron (II) Nitride, how many grams of Iron (Fe) do I make? 

84 g Fe