Stoich basics
Moles to Moles
Limiting Reagents
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Miscellaneous
100

Balance the following chemical equation:  

CH₄ + O₂ → CO₂ + H₂O

Balanced: CH₄ + 2O₂ → CO₂ + 2H₂O

100
CO2 + 2LiOH --> Li2CO3 + H2O How many moles of lithium hydroxide are required to react with 20 mol of CO2?
What is 40 mol LiOH?
100

10.0 grams of nitrogen gas (N₂) react with 3.0 grams of hydrogen gas (H₂) to form ammonia (NH₃).  Which reactant is the limiting reactant?

N₂ + 3H₂ → 2NH₃  

 N₂ is the limiting reactant.

100

10.0 grams of reactant A are reacted and should theoretically produce 15.0 grams of product B.  If only 12.0 grams of product B are actually collected, what is the percent yield of the reaction?

80%

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

Predict the products and balance the following reaction:  Zn + HCl →

Balanced: Zn + 2HCl → ZnCl₂ + H₂

200
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?
200

If 5.0 grams of magnesium (Mg) reacts with 8.0 grams of oxygen (O₂) to produce magnesium oxide (MgO), what mass of MgO will be produced?

2Mg + O₂ → 2MgO

 (Molar masses: Mg = 24.3 g/mol, O = 16.0 g/mol)   




8.3 g MgO

200

If you react 5.0 grams of sodium bicarbonate (NaHCO₃) with excess hydrochloric acid (HCl), what is the percent yield of carbon dioxide (CO₂) if you collect 2.2 grams of CO₂?  (NaHCO₃ = 84 g/mol, CO₂ = 44 g/mol).

2.62 g CO₂

200
Avogadro's number.
What is 6.022 x 10^23?
300

Predict the products and balance 

  AgNO₃(aq) + NaCl(aq) →

Balanced: 

AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq)

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

2.5 moles of aluminum (Al) react with 4.0 moles of hydrochloric acid (HCl) according to the following balanced equation: 2Al + 6HCl → 2AlCl₃ + 3H₂.  

How many moles of hydrogen gas (H₂) will be produced?

2.0 mol H₂

300

10.0 grams of magnesium (Mg) are reacted with 20.0 grams of oxygen (O₂) to produce magnesium oxide (MgO).  

If 15.0 grams of MgO are collected, what is the percent yield? (Molar masses: Mg = 24.3 g/mol, O = 16.0 g/mol, MgO = 40.3 g/mol).

90.4%

300
How many moles are present in 34 grams of Cu(OH)2?
What is 0.35 mol Cu(OH)2?
400

Predict the products and balance the complete combustion of propane 

(C₃H₈): C₃H₈ + O₂ →

Balanced: C₃H₈ + 5O₂ → 3CO₂ + 4H₂O

400
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?
400

15.0 grams of iron (Fe) reacts with 10.0 grams of sulfur (S) to form iron(II) sulfide (FeS).  Which reactant is limiting?  How many grams of the excess reactant will remain after the reaction is complete? (Molar masses: Fe = 55.8 g/mol, S = 32.1 g/mol)

1.36 g S remaining

400

A three-step reaction sequence has the following percent yields for each step: Step 1: 85%, Step 2: 92%, Step 3: 75%. If you start with 25.0 grams of the initial reactant, what mass of the final product would you expect to obtain (assuming the theoretical yield is 100% at each step based on the starting amount)?

14.7 g

400
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.
What is: 2LiOH (s) + H2SO4 (aq) --> Li2SO4 (aq) + 2H2O (l)
500

Predict the products and balance the following double replacement reaction:

K₂CO₃(aq) + BaCl₂(aq) →

Balanced: 

K₂CO₃ + BaCl₂ → 2KCl + BaCO₃

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

You want to produce 10.0 grams of pure product C.  The reaction to produce C has a 70% yield.  If the starting material (A) is only 80% pure, what mass of the impure starting material A do you need to begin with to theoretically obtain your desired 10.0 grams of pure C?

17.86 g

500
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?
What is 188 g KCl?
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