Stoichiometry 5th Year

The of a compound is a formula which shows the number and type of each atom present in a molecule of that compound

• Mass number

• Chemical formula

• Empirical formula

• Molecular formula

The of a compound is the formula showing the simplest whole number ration of the numbers of different atoms present in the molecule

• Mass number

• Chemical formula

• Empirical formula

• Molecular formula

Calculate the percentage composition by mass of Sodium in NaCl ( Na = 11, Cl = 35.5)

• 23.7%

• 46.6%

• 50%

• 66.3%

Hexane is a simple hydrocarbon used in industry to extract oils from seeds. It has an empirical formula of C3H7. The relative molecular mass was found to be 86. What is the molecular formula of Hexane given:

C = 12 H = 1

• C₆H₁₂

• C₆H₁₄

• C6H₁₂O₆

• C₁₂H₁₂

• CuO₂

• CO

• CuO

• CUO

• 15

• 25

• 48

• 80

• 98g

• 112g

• 100g

• 56%