Stoichiometry

What is a Limiting Reagent?

• speeds up a reaction

• what you run out of first

• what you have left over

• slows down a reaction

When does a chemical reaction stop?

• When the lab is finished

• When the excess reactant is used up

• When the limiting reactant is used up

• Chemical reactions never stop

The empirical formula is the formula that includes only the simplest whole

number ratio of elements in a compound

• True

• False

Determine the empirical formula for a compound with the following percent composition: 15.8% carbon and 84.2% sulfur

(molar masses: C = 12.011 g/mol, S = 32.065 g/mol)

Tags

NGSS.HS-PS1-3

SiO₂ + 3C → SiC + 2CO
I need to add 8 moles of Carbon to the reaction. How many grams of Carbon should I weigh?

• _{96 g}

• 0.67 g

• 2.67 g

• 48 g

How many liters of NH₃ are needed to react completely with 30.0L of NO?
4NH₃+6NO --> 5N₂ + 6H₂O

• 5.0 L

• 20.0 L

• 7.5 L

• 120.0 L

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

Use the equation 2 Al + 3 Cl₂ ---> 2 AlCl₃.  If 2 moles of aluminum and 2 moles of chlorine are reacted, identify the limiting reactant.

• AlCl3

• Cl2

• Al

Tags

NGSS.HS-PS1-7

4NH₃ + 5O₂ --> 4NO + 6H₂O
How many grams of NO are formed if 6.30g of ammonia react with 1.80g of oxygen? 

• 0.37g

• 0.045g

• 1.35g

• 11.1g

Tags

NGSS.HS-PS1-7

How many grams of sodium would be produced by the decomposition of 4.85 grams of sodium chloride?

• 1.91 grams Na

• 3.56 grams Na

• 1.16 grams Na

• 2.54 grams Na

Tags

NGSS.HS-PS1-7