1. Which of the following formula equations matches the word equation below: Magnesium + hydrogen monochloride  Magnesium chloride + hydrogen a. Mg + HCl  MgCl + H b. Mg + HCl  MgCl + H 2 c. Mg + HCl  MgCl 2 + H 2 d. Mg 2 + HCl  MgCl + H 2 e. Mg 2 + HCl  MgCl 2 + H 2 2. Circle the reactants in the reaction below: CaCl 2 + LiBr  LiCl + CaBr 2 3. If you start with 4 grams of CaCl 2 and 8 grams of LiBr how much combined LiCl and CaBr 2 will you have?

Conservation of mass and balancing equations

To show that during a chemical reaction mass can not be created or destroyed. To show that we have the same number of each type of atom before and after a reaction.

CO 2 One atom of carbon Two atoms of oxygen OR 1 mole of carbon 2 moles of oxygen

3 CO 2 The Coefficient (3) triples the amount of everything… 3 CO 2 = CO 2 + CO 2 + CO 2

3 CO 2 Three atoms of carbon Six atoms of oxygen Or Three moles of carbon Six moles of oxygen

CO 2 Answer: 1 C 2 O 3 CO 2 H 2 O Mg(OH) 2 2 Mg(OH) 2 3 (NH 4 ) 2 CO 3 C 6 H 12 O 6 Mg(C 2 H 3 O 2 ) 2 2 CH 3 CH 2 OH CuCl 2 ● 12 H 2 O Write down each formula and how many atoms (or moles of each element it shows. 3 C 6 O 2 H 1 O 1 Mg 2 O 2 H 2 Mg 4 O 4H 6 N 24 H 3 C 9 O 6 C 12 H 6 O 1 Mg 4 C 6 H 4 O 4 C 12 H 2 O 1 Cu 2Cl 24 H 12 O

NaCl + AgNO 3 NaNO 3 + AgCl 1 Na 1 1 Cl 1 1 Ag 1 1 N 1 3 O 3 This Reaction is already balanced!

H 2 O H 2 + O 2 2 H 2 1 O 2 This Reaction is not balanced! We must add coefficients to balance it

Fe 2 O 3 + CO Fe + CO 2 2 Fe 1 4 O 2 1C 1 This Reaction is not balanced! We must add coefficient to balance it

HCl + Al  H 2 + AlCl 3 1. Balance the reaction. 2. Convert the equation into a sentence.