CHEMICAL EQUATIONS

PRACTICE:

– BALANCING FOR CONSERVATION OF MASS– TYPES OF REACTIONS

A Three Step Approach

• First a word equation is written to summarize the reaction in words.

hydrogen + oxygen waterThe above is read as: Hydrogen gas molecules react with oxygen gas molecules to produce water molecules

• Then a skeleton equation is written with all the correct formulas for the substances.

H2(g) + O2 (g) H2O(l)

• Then the equation is balanced for conservation of mass. (Large multipliers are placed in front of substances to balance the equation)

• 2H2 + O2 2H2O

Step 1: Summarize the text into a word equation

silver nitrate + copper copper(I) nitrate + silverStep 2: Write the skeleton equation. (It has correctly charge-balanced FORMULAS. )

AgNO3 + Cu Cu NO3 + Ag Step 3: Balance the equation for conservation of mass.

1 AgNO3 + 1 Cu 1 Cu NO3 + 1 Ag

PRACTICE-1

• The types of chemical reactions can be used to predict possible products given the reactants.

• The reaction is then done and the products are observed to verify the prediction. What evidence would you look for in the following reaction?

• silver nitrate reacts with copper to produce copper(I) . . . TYPE single replacement

Step 1: Summarize the text into a word equation

magnesium metal + hydrochloric acid ) magnesium chloride + hydrogen gasStep 2: Write the skeleton equation. (It has correctly charge-balanced FORMULAS. )

Mg (s) + HCl(aq) MgCl2 +H2 (g)

Step 3: Balance the equation for conservation of mass.

1 Mg (s)+ 2 HCl(aq) 1 MgCl2 + 1 H2 (g)

PRACTICE-2

• The types of chemical reactions can be used to predict possible products given the reactants.

• The reaction is then done and the products are observed to verify the prediction. What evidence would you look for in the following reaction?

• magnesium metal reacts with hydrochloric acid to produce TYPE single replacement

Step 1: Summarize the text into a word equation

iron metal + oxygen gas Iron (lll) oxideStep 2: Write the skeleton equation. (It has correctly charge-balanced FORMULAS. )

Fe (s) + O2 (g) Fe2O3 (s)

Step 3: Balance the equation for conservation of mass.

4 Fe (s)+ 3 O2(g) 2 Fe2O3 (s)

PRACTICE-3

• The types of chemical reactions can be used to predict possible products given the reactants.

• The reaction is then done and the products are observed to verify the prediction. What evidence would you look for in the following reaction?

• iron metal reacts with oxygen to produce Iron (lll) . . . TYPE simple addition

Step 1: Summarize the text into a word equation

mercury metal + oxygen gas mercury (l) oxideStep 2: Write the skeleton equation. (It has correctly charge-balanced FORMULAS. )

Hg(s) + O2 (g) Hg2O (s)

Step 3: Balance the equation for conservation of mass.

4 Hg (s)+ 1 O2(g) 2 Hg2O (s)

PRACTICE-4

• The types of chemical reactions can be used to predict possible products given the reactants.

• The reaction is then done and the products are observed to verify the prediction. What evidence would you look for in the following reaction?

• mercury reacts with oxygen to produce mercury (l) . . . TYPE simple addition

Step 1: Summarize the text into a word equation

silver nitrate + magnesium chloride magnesium nitrate + silver chlorideStep 2: Write the skeleton equation. (It has correctly charge-balanced FORMULAS. )

AgNO3 (aq)+ MgCl2 (aq) Mg(NO3)2 (aq)+ AgCl (s)

Step 3: Balance the equation for conservation of mass.

2AgNO3 (aq)+ 1MgCl2 (aq) 1Mg(NO3)2 (aq)+ 2AgCl (s)

PRACTICE-5

• The types of chemical reactions can be used to predict possible products given the reactants.

• The reaction is then done and the products are observed to verify the prediction. What evidence would you look for in the following reaction?

• silver nitrate reacts reacts with magnesium chloride to produce . . . TYPE double replacement

Step 1: Summarize the text into a word equation

potassium chlorate potassium chloride + oxygenStep 2: Write the skeleton equation. (It has correctly charge-balanced FORMULAS. )

KClO3 (aq KCl (s)+ O2 (g)

Step 3: Balance the equation for conservation of mass.

2KClO3 (aq 2KCl (s)+ 3O2

PRACTICE-6

• The types of chemical reactions can be used to predict possible products given the reactants.

• The reaction is then done and the products are observed to verify the prediction. What evidence would you look for in the following reaction?

• potassium chlorate when heated produces . . . TYPE decomposition

Step 1: Summarize the text into a word equation

calcium carbonate calcium oxide + carbon dioxideStep 2: Write the skeleton equation. (It has correctly charge-balanced FORMULAS. )

CaCO3 (s) CaO (s)+ CO2 (g)

Step 3: Balance the equation for conservation of mass.

1CaCO3 (s) 1 CaO (s)+ 1CO2 (g)

PRACTICE-7

• The types of chemical reactions can be used to predict possible products given the reactants.

• The reaction is then done and the products are observed to verify the prediction. What evidence would you look for in the following reaction?

• calcium carbonate when heated produces . . . TYPE decomposition

Step 1: Summarize the text into a word equation

copper(l) nitrate + mercury(l1) chloride mercury(1l) nitrate + copper(1) chlorideStep 2: Write the skeleton equation. (It has correctly charge-balanced FORMULAS. )

2CuNO3 (aq)+ 1HgCl2 (aq) 1Hg(NO3)2 (aq)+ 2CuCl (s)

Step 3: Balance the equation for conservation of mass.

2CuNO3 (aq)+ 1HgCl2 (aq) 1Hg(NO3)2 (aq)+ 2CuCl (s)

PRACTICE-8

• The types of chemical reactions can be used to predict possible products given the reactants.

• The reaction is then done and the products are observed to verify the prediction. What evidence would you look for in the following reaction?

• Copper(1)nitrate reacts with mercury(ll) chloride to produce . . . TYPE double replacement

Step 1: Summarize the text into a word equation

methane gas + oxygen gas carbon dioxide + waterStep 2: Write the skeleton equation. (It has correctly charge-balanced FORMULAS. )

CH4(g) + O2 (g) CO2(g) + H2O (g)

Step 3: Balance the equation for conservation of mass.

1 CH4(g) + 2O2 (g) 1CO2(g) + 2H2O (g)

PRACTICE-9

• The types of chemical reactions can be used to predict possible products given the reactants.

• The reaction is then done and the products are observed to verify the prediction. What evidence would you look for in the following reaction?

• methane “CH4(g)” reacts with oxygen to produce . . . TYPE hydrocarbon combustion

Step 1: Summarize the text into a word equation

butane gas + oxygen gas carbon dioxide + waterStep 2: Write the skeleton equation. (It has correctly charge-balanced FORMULAS. )

C4H10(g) + O2 (g) CO2(g) + H2O (g)

Step 3: Balance the equation for conservation of mass.

2 [1 C4H10(g) + 13/2O2 (g) 4CO2(g) + 5H2O (g)]

2 C4H10(g) + 13O2 (g) 8CO2(g) + 10H2O (g)]

PRACTICE-10

• The types of chemical reactions can be used to predict possible products given the reactants.

• The reaction is then done and the products are observed to verify the prediction. What evidence would you look for in the following reaction?

• butane C4H10(g) reacts with oxygen to produce . . . TYPE hydrocarbon combustion