Chemistry Standard 3 Review

According to the Law of Conservation of Mass... (more than one correct)

• atoms are either lost or gained after a chemical reaction

• # of atoms before a chemical reaction will equal # of atoms after a chemical reaction

• a physical change is when # of atoms stays the same. chemical change is when # of atoms increases

• matter/mass is neither lost nor gained during a chemical reaction

To find moles ...

• subtract total moles on product side from total moles on reactant side

• divide grams and molar mass

• multiply moles and molar mass

• divide grams by 0.025

molar mass is ...

• the mass of one mole of the given element or compound

• the same as an element's atomic number

• the same as an element's # of protons

How many moles are in 156 grams of sodium sulfide?

• 0.25 mol

• 2 mol

• 3 mol

• 0.5 mol

Stoichiometry is ...

• the study of different types of matter

• the study of atoms and their properties

• the study of the amounts of the substances involved in chemical reactions

• the study of reactions between different molecules

To find grams ...

• divide grams and molar mass

• multiply moles and molar mass

• divide moles and molar mass

• find the decimal number on the periodic table

Balance the following equation

• 1, 1, 2, 3

• 1, 2, 2, 2

• 2, 1, 3, 1

• 1, 2, 3, 2

Predict the product for the following reaction:

Balance the equation

• 1, 1, 1 (already balanced)

• 1, 2, 1

• 2, 1, 2

• 2, 1, 3

What is the molar mass of NaCl?

• 50 g/mol

• 25 g/mol

• 58.5 g/mol

• 63.5 g/mol