Why do you need to convert the mass to moles in stoichiometric calculation?

Tags

NGSS.HS-PS1-7

What is the mole ratio of  $H_2O$   to  $H_3PO_4$   in the following chemical equation?

  $P_4O_{10}\ +\ 6H_2O\ \longrightarrow\ 4H_3PO_4$  

• 6:4

• 4:6

• 1:3

• 3:1

Tags

NGSS.HS-PS1-7

Using the following equation:
Fe₂O₃(s) + 3H₂(g) → 2Fe(s) + 3H₂O(l)
How many moles of iron can be made from  6 moles H₂? 

• 4 moles Fe
• 6 moles Fe
• 9 moles Fe
• 2 moles Fe

Tags

NGSS.HS-PS1-7

2Al + 3H₂SO₄ -> Al₂(SO₄)₃ + 3H₂
How many grams of aluminum sulfate would be formed if 250g H₂SO₄ completely reacted with aluminum?

• 0.85 g
• 290 g
• 450 g
• 870 g

Tags

NGSS.HS-PS1-7

A student burns 1.50 mol C₃H₈ according to the following reaction:

C₃H₈ + 5O₂ → 3CO₂ + 4H₂O

How many grams of carbon dioxide are produced?

• 44.0 g

• 66.1 g

• 132 g

• 198 g

Tags

NGSS.HS-PS1-7

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

• Fe
• S
• FeS
• none 

Tags

NGSS.HS-PS1-7

You need 2 pieces of bread, 1 tablespoon of peanut butter and 2 tablespoons of jelly to make a sandwich.  If you have 10 pieces of bread, 4 tablespoons of peanut butter and 20 tablespoons of jelly, what is the limiting reactant?

• bread
• jelly
• peanut butter
• sandwich

Tags

NGSS.HS-PS1-2

For the Balanced Reaction: 3 Mg + 1 Fe₂O₃ → 3 MgO + 2 Fe; 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

Tags

NGSS.HS-PS1-7

Cl₂ + 2KBr → Br₂ + 2KCl
How many grams of potassium chloride (KCl) can be produced from 356 g of potassium bromide (KBr)?

• 749 g
• 223 g
• 479 g
• 814 g

Tags

NGSS.HS-PS1-7

What is a Excess Reagent?

• amount you end with
• what you run out of first
• what you have left over
• what you start with

Tags

NGSS.HS-PS1-7