Topic 1 Topic 2 Topic 3 Topic 4 Topic 5 10 10 10 10 10 20 20 20 20 20 30 30 30 30 30 40 40 40 40 40 50 50 50 50 50
Question 1-10 Oxygen gas is written as O 2 in chemical equations. What term is used to describe the 2 in this formula? A. product B. coefficient C. catalyst D. subscript
Answer 1 10 D. subscript A subscript is the small number below an element
Question 1-20 What term is used to describe the 4 in the expression 4Ca(NO 3 ) 2? A. coefficient B. formula C. subscript D. symbol
Answer 1 20 A. coefficient A coefficient is the big number in front
Question 1-30 Which of the following types of reactions is the opposite of a synthesis reaction? A. displacement B. reversible C. combustion D. decomposition
Answer 1 30 D. decomposition Decomposition (breaking apart) is the opposite of synthesis (putting together)
Question 1-40 Which of the following processes is endothermic? A. burning wood B. exploding dynamite C. melting ice D. freezing water
Answer 1 40 C. melting ice Melting ice is endothermic because you add heat to melt the ice
Question 1-50 Which diagram below shows the correct location of the reactants and products of a chemical reaction? A. reactants products B. products reactants
Answer 1 50 A. reactants products Reactants are before the arrow; products after because they are what s produced
Question 2-10 When a chemical equation is balanced it shows that A. mass is conserved B. energy is conserved C. nothing is conserved
Answer 2 10 A. mass is conserved A balanced equation shows that mass is conserved
Question 2-20 In a combustion reaction, oxygen gas is a A. reactant B. product C. neither
Answer 2 20 A. reactant Oxygen gas is a reactant is a combustion reaction
Question 2-30 Food preservatives are added to slow down the chemical reaction that makes food go bad. In this case, food preservatives are A. catalysts B. products C. inhibitors
Answer 2 30 C. inhibitors Food preservatives are inhibitors because they slow down a chemical reaction of the food aging
Question 2-40 A substance that produces hydrogen ions in solution is a(n) A. acid B. base
Answer 2 40 A. acid An acid produces Hydrogen ions
Question 2-50 The sour taste of citrus fruits is caused by the presence of in these foods. A. acid B. base
Answer 2 50 A. acid Acids taste sour
Question 3-10 A substance that breaks apart completely in a solution is called a A. strong acid/base B. weak acid/ base C. dilute acid/base
Answer 3 10 A. strong acid/base A strong acid/base breaks apart completely
Question 3-20 On the ph scale, a ph of 7 indicates that something is A. acidic B. basic C. neutral
Answer 3 20 C. neutral ph of 7 is neutral
Question 3-30 The ph of lemon juice is most likely close to A. 7 B. 3 C. 10 D. 11
Answer 3 30 B. 3 Lemon juice is an acid so its ph is below 7
Question 3-40 Antacids work because they excess stomach acid. A. contain B. neutralize C. acidify D. concentrate
Answer 3 40 B. neutralize Antacids work against stomach acid to neutralize acid
Question 3-50 A solution with a bitter taste and a slippery feel is most likely A. an acid B. a base C. salt D. a chemical
Answer 3 50 B. a base Bases taste bitter and are slippery
Question 4-10 When you wash your hands with soap you are using a A. buffer B. acid C. base D. indicator
Answer 4 10 C. base Soap is a base (slippery)
Question 4-20 Balance the equation below: H 2 + O 2 H 2 O
Answer 4 20 _2_H 2 + 1 O 2 2 H 2 O
Question 4-30 Balance the equation: P + O 2 P 4 O 10
Answer 4 30 4 P + _5 O 2 1 P 4 O 10
Question 4-40 Balance the equation: Ag 2 O Ag + O 2
Answer 4 40 2 Ag 2 O 4 Ag + 1 O 2
Question 4-50 Balance the equation: K + MgBr KBr + Mg
Answer 4 50 1 K + 1 MgBr 1 KBr + 1 Mg
Question 5-10 Balance the equation: H 2 O + O 2 H 2 O 2
Answer 5 10 2 H 2 O + 1 O 2 2 H 2 O 2
Question 5-20 Type of chemical reaction? C 10 H 8 + 12 O 2 10 CO 2 + 4 H 2 O
Answer 5 20 Combustion- combines with oxygen and makes carbon dioxide and water
Question 5-30 Type of reaction? NaCl + AgNO 3 NaNO 3 + AgCl
Answer 5 30 Double displacement-each element in the compound switches and forms a new compound
Question 5-40 Reaction type? Zn + 2 HCl ZnCl 2 + H 2
Answer 5 40 Single displacement-one element in the compound is replaced. One element is by itself
Question 5-50 Reaction type? 8 Fe + S 8 8 FeS
Answer 5 50 Synthesis-two elements form a compound
Question 6-60 What is the reaction type? 2 H 2 O 2 H 2 + O 2
Answer 6-60 Decomposition-a compound breaks apart into separate elements