Ch 11 Test Hints – Chemistry Balancing Equations

1) Define/identify what chemical reactions are You should be able to explain what happens to atoms in a chemical reaction.

2) Describe what a chemical equation shows. Make sure you understand the difference between a chemical EQUATION and a chemical reaction.

3) Define skeleton equation. This is one of those “which of the following is NOT” type of questions. Make sure you understand the difference between the skeleton and the balanced equation.

4) Define catalyst. What does a catalyst do in a reaction and what does the catalyst “look” like at the end of the reaction?

5) Identify the correct skeleton equation given a word description of the reaction. You need to be able to identify the reactants and products from a written description of a chemical reaction. Again, you need to know how a skeleton equation is different from a balanced equation. See p. 324 practice problem #2 in your book. P. 329 #10 & 11 give you great chances to practice this! Whoo!

6) Write a balanced equation from a word equation. We will give you the specific reactants and products in words, you just have to write the formulas AND BALANCE it! Check out the many balancing equations worksheets that we did for a bunch of examples. See p. 328, practice problem #6

7) Balance a skeleton equation. p. 328 practice problem 5 and #12 on p. 329 – exactly the same thing!!

8) Identify what is equal on both sides of a chemical equation (how do we know an equation is balanced?) As in, what are you counting??????

9) Balance a skeleton equation. Formulas are given, you have to count and balance. Check your many balancing worksheets. p. 347 #43 has 4 awesome opportunities to practice balancing AND the answers are in the back of the book.

10) Balance an equation given a word description of the reaction. Make sure you practice double replacement reactions and go back over Lab 15.

11) Identify the more active reactant in a single replacement reaction You need to know which element can replace the other. Check your Fe + CuSO4 lab. Why could Fe replace Cu? (and why can’t it replace SO4 ?)

12) Identify the possible products in a combustion reaction. This is another “products of a combustion reaction do NOT include…” type of problem. If you know the 2 super-common products of ALL combustion reactions, this should be a cinch!

13) Describe the reactants and products in a double replacement reaction. You need to know what KINDS of compounds are involved in this type of reaction. See Lab 15 again for some examples 

14) Write the balanced equation for the decomposition of a metal oxide. Ok. We were totally serious when we said you have to know ALL 6 kinds of decomposition reactions, not just that decomposition means breaking down. PLUS you need to identify the correctly-balanced equation.

15) Complete a balanced double replacement reaction given the reactants. This is a reaction prediction problem. We practiced these on several worksheets and Lab 15. Make sure you go back and watch the podcasts on Moodle for double replacement (same as double displacement)

16) Balance a combustion reaction given the fuel (the stuff that is burning) You MUST know the other reactant and the only 2 possible products of a combustion reaction. We even give you 2 big giant hints on how to set up and balance this equation right in the question.

17) Complete a balanced single replacement reaction given the reactants You need to consider the activity series on this one for sure!! Remember that metals replace metals and nonmetals replace nonmetals.

18) Predict the products of a double replacement reaction given the reactants. The formulas of the reactants are provided, but you need to know what they form in this type of reaction. You absolutely, positively MUST know how to write correct chemical FORMULAS before you try to balance this.

19) Identify the type of reaction given a balanced chemical equation. You need to know the general form of all 5 types of reactions. This one will be pretty straightforward. You will be given a balanced chemical equation and have to tell what kind it is.

20) Identify the type of reaction given a balanced chemical equation. You need to know the general form of all 5 types of reactions. This one will be pretty straightforward, we have done a lab that is similar. You will be given a balanced chemical equation and have to tell what kind it is.

21) Identify the type of reaction given a balanced chemical equation. You need to know the general form of all 5 types of reactions. This one will be pretty straightforward. You have done a lab with many similar reactions! You will be given a balanced chemical equation and have to tell what kind it is.

22) Identify the balanced equation given the word description of the reactants. We will give you the names of the reactants and you have to be able to predict the products. See the Reaction Types and Reaction Prediction worksheets for lots of examples. Your book will help too!! When you carefully consider each answer choice, be sure to look for correctly-written chemical formulas and then correctly balanced equations.

23) Identify the driving force (why the reaction occurs) in a double replacement reaction. You need to know why single and double replacement reactions occur. One type has to do with the activity series and the other has to do with solubility rules . There are great charts for both of these in your book ! Check out the podcasts again on our Moodle pages. They give you great examples as well.

24) Balance an equation given the skeleton equation. Short answer problem time! This problem will give you a word AND a skeleton equation. You just have to balance it with coefficients. This is an “everyday model” example.

25) Write the balanced equation for a double replacement reaction given the reactants. Short answer. You will be give the correct formulas of the reactants. You have to write the correct formulas of the products and then balance.

26) Balance the skeleton equation. Short answer. You will be give the correct formulas of the reactants. You have to write the correct formulas of the products and then balance. You will also have to tell what KIND of reaction this is!

27) Write the balanced equation for a single replacement reaction given the reactants. Short answer. You will be give the correct formulas of the reactants. You have to write the correct formulas of the products and then balance.

28) Write the balanced equation for the decomposition reaction given the reactants. Short answer. You will be give the correct formulas of the reactants. You have to write the correct formulas of the products and then balance.

29) Write the balanced equation for the combination reaction given the reactants. Short answer. You will be give the correct formulas of the reactants. You have to write the correct formulas of the products and then balance.

30) Write the balanced equation for the combustion reaction given the reactants. Short answer. You will be give the correct formulas of the reactants. You have to write the correct formulas of the products and then balance.