Stoichiometry Mass and Mole Calculations

What is the mole ratio of H₂O to H₃PO₄ in the following chemical equation?  

P₄O₁₀ + 6 H₂O --> 4 H₃PO₄ 

• 6:4

• 4:6

• 1:3

• 3:1

Identify the limiting reagent when 6.00 g HCl combines with 5.00 g Mg to form MgCl₂.
 
Mg +  2HCl --> MgCl₂  +  H₂   
 

• Mg

• H2

• MgCl2

• HCl

LiOH + KCl → LiCl + KOH 

6.0g of LiCl was produced in an experiment. However, through stoichiometry calculations, it was found that 35.5g of LiCl should have been produced. What is the percent yield?

• 16.9%

• 5.91%

• 1.88%

• 12.3%

What is the Ratio of moles of MgO to moles Fe?

• 3mol Mg / 2 mol Fe

• 2 mol Mg/ 3 mol Fe

• 1 mol Fe/ 2 mol Fe

• 3 mol MgO / 2 mol Fe

In a chemical reaction, the mass of reactants ___.

• is less than the mass of products

• is greater than the mass of products

• has no relationship to the mass of products

• is equal to the mass of products

Tags

NGSS.MS-PS1-5

In a balanced equation, the ratio between the coefficient of any two substances is called the _______.

• mole ratio

• stoichiometry

• limiting reactant

• excess reactant

In the image, which reactant is limiting?

• The white molecules, because there are extra.

• The black atoms, because they are completely used up.

• The white molecules, because they are completely used up.

• The black atoms, because there are extra.

Tags

NGSS.MS-PS1-2

CH₄ + 2H₂O --> CO₂ + 4H₂
What is the limiting reactant when 20g CH₄ react with 15g H₂O?

• CH₄

• H₂O

• CO₂

• H₂

Fe + S --> FeS
If 7.62g Fe react with 8.67g S, what is the limiting reactant?

• Fe

• S

• FeS

• none 

• 18 grams

• 36 grams

• 72 grams

• 144 grams