Stoichiometry and more! Spring 2021

Formulas & Equations

100

Iron (III) oxide

Fe₂O₃

200

Write the balanced equation for when hydrogen and oxygen gas combine. 

2 H2 + O2 --> 2 H2O

300

Compound produced from the combination of calcium and aluminum phosphate. 

Ca₃(PO₄)₂

400

Balanced equation for the combustion of octane, C₈H₁₈

2 C₈H₁₈ + 25 O₂ --> 16 CO₂ + 18 H₂O

500

Balanced equation for the reaction of sodium carbonate and magnesium hydroxide. 

Na₂CO₃ + Mg(OH)₂ --> 2 NaOH + MgCO₃

Moles

100

Number of water bottles in one mole

6.02 x 10²³

200

Number of grams in 3 moles of helium

12g He

300

Number of moles in 49.25g of gold

0.25 moles. 

400

Number of moles of calcium needed for each mole of each mole of water. 

Ca + 2H₂O --> Ca(OH)₂ + H₂

2 moles of Ca needed for each 1 mole of H₂O

500

Number of moles of lithium oxide needed to react with magnesium chloride to create 120g of the product with magnesium. 

Li₂O + MgCl₂ --> 2 LiCl + MgO

120g MgO x 1 mole MgO. x. 1 mol Li₂O = 3 mol Li₂O

     1.           40g MgO.         1 mol MgO

Mass-Mole conversions

100

The number of mole ratios possible with the following equation.

AlCl₃ + Na₂O --> NaCl + Al₂O₃

six

200

How many moles of AlCl₃ are needed to create 15.3 mol of NaCl?

AlCl₃ + Na₂O --> NaCl + Al₂O₃

5.10 mol AlCl₃

300

How many grams of Al₂O₃ are created when  36.00mol of NaCl forms?

AlCl₃ + Na₂O --> NaCl + Al₂O₃

612.0 grams Al₂O₃

400

How many grams of Na₂O are needed to create 118 grams of NaCl?

AlCl₃ + Na₂O --> NaCl + Al₂O₃

62.5g Na₂O

500

***How many atoms of sodium when 517.0 grams of AlCl₃ react in the equation below? 

AlCl₃ + Na₂O --> NaCl + Al₂O₃

6.994 x 10²⁴ atoms

Limiting reactant and gas law application

100

What reactant restricts the formation of product?

Limiting reactant

200

1.5 mol of ethane (C₂H₆) combine with 4.0 mol of oxygen in a combustion reaction.  

Determine the limiting reactant. 

Oxygen is limiting

300

What is the maximum number of moles of carbon dioxide that can be produced with 414 grams of oxygen and 589 grams of ethane?

7.39 mol CO2 can be produced. 

400

What is the maximum number of grams of water that can be produced with 520 grams of oxygen and 670 grams of ethane?

250 grams H₂O

500

What is the number of excess reactant in grams if 520 grams of oxygen and 670 grams of ethane?

530 grams of ethane remain

Nuclear

100

The spontaneous breakdown of an isotope into a different isotope. 

Radioactive decay

200

The time needed for one half of the mass of an isotope to decay

Half-life

300

Particle made of 2 protons and 2 electrons,

Particle that changes a neutron to a proton

Type high frequency electromagnetic radiation given off during decay. 

Alpha, Beta, Gamma

400

A rock has 4.3mg of Potassium-40. The rock was dated 3.84 billion years old. How much Potassium-40 was originally present?  (1 half-life = 1.28 billion years)

34.4 grams

500

Plutonium-242 releases an alpha particle during decay.  Write the equation for the decay. 

²⁴²₉₄Pu --> ⁴₂He + ²³⁸₉₂U