Science Chapter 7 Test
inhibitor
A catalyst that slows a reaction is called a(n) _________
C
A chemical equation is balanced by changing or adding A- chemical symbols B- subscripts C- coefficients D- reactants
exothermic
A chemical reaction that transfers energy from the reactants to the surroundings is referred to as ________
A
A release of energy is a sign that A-a chemical change is taking place B-a physical change has just occurred C-oxygen is present D-organic chemicals are present
C
A substance that undergoes a change in a chemical reaction is A- a product B- a chemical C- a reactant D- an enzyme
C
A synthesis reaction between magnesium (Mg) and oxygen (O2) might produce A- Mg2 B- O4 C- MgO D- MgCO2
B
A type of reaction that produces an increase in temperature is A-endothermic B-exothermic C-covalent D-nonpolar
A
All of the following factors may speed up a chemical reaction except A-smaller surface area B-higher pressure C-higher temperature D-presence of a catalyst
A
All of these are likely to speed up the rate of a reaction except A- decreasing the surface area B- increasing the pressure C- increasing the temperature D- adding a catalyst
Copper
Aluminum undergoes a single-displacement reaction with copper (II) sulfate to form aluminum sulfate and ___________
A
An enzyme is a special kind of catalyst that works to A- speed up a specific biochemical reaction B- slow down a chemical reaction C- break down chemical elements D- maintain the correct temperature for a reaction
protein, catalyst
An enzyme is a(n) _________ that acts as a(n)_________ in a chemical reaction that takes place in a living thing
2
Balance the following chemical equation by filling in the correct coefficient on the right-hand side. H2 + Cl2 --> ________KBr + I2
2, 2
Balance the following chemical equation by filling in the correct coefficients. _______ KI + Br2 --> _______ KBr + I2
A
Catalysts that slow reactions are called A- inhibitors B- substrates C- balanced D- endothermic
D
In a balanced chemical equation, the mass of the reactants is equal to the A- atoms in a molecule B- atomic mass of the elements C- volume of the reactants D- mass of the products
C
In a balanced chemical reaction, the total mass of the products always equals the A- molar mass of the reactants B- atomic mass of the reactants C- total mass of the reactants D- proportional masses of the reactants
decompostition
In a(n)__________ reaction, the reactants are broken down into other substances
A
In an exothermic reaction, energy is transferred from A- the reactants to the surroundings B- the surroundings to the reactants C- one reactant to another D- the container to the chemicals
A+B=AB
The general formula for a synthesis reaction is _________
D
The substance that is formed in a chemical reaction is called the A-polymer B-reactant C-radical D-product
B
What coefficient is missing in C2H4+(?)O2-->2CO2+2H20 A- 2 B- 3 C- 4 D- 5
D
What happens in a chemical reaction? A- Atoms are destroyed B- atoms are created C- atoms are heated and cooled D- atoms are rearranged
single-displacement reaction
What kind of reaction is this: 2Li + 2H2O --> 2LiOH + H2
decomposition reaction
What kind of reaction is this: 2NH3 --> N2 + 3H2
combustion reaction
What kind of reaction is this: CH4 + 2O2 --> CO2 + 2H2O
synthesis reaction
What kind of reaction is this: Fe + S --> FeS
A
Which is not true of catalysts? A- They are used up in a reaction B- They can speed up a reaction C- they can slow down a reaction D- They can be reused
D
Which is not true of enzymes? A- they are catalysts B- they are proteins C- they are affected by temperature D- they are inefficient
D
Which of the following equations is not balanced? A- Fe + S --> FeS B- KOH + HCl --> KCl + H2O C- 2Mg + O2 --> 2MgO D- NaCl + H2SO4 --> Na2SO4 + HCl
B
Which of the following occurs in an endothermic reaction but not in an exothermic reaction? A-chemical bonds are broken B-Energy is absorbed C-molecules are formed D-atoms are rearranged
B
Which statement about endothermic reactions is correct? A- energy is always created in the form of heat B- energy is transferred from the surroundings to the reactants C- energy is used to force electrons to move to higher energy levels D- energy is transferred from the reactants to the surroundings.
D
a synthesis reaction is a reaction between at least two compounds in which A- one breaks down into at least two products B- a compound is decomposed by an electric current C- a compound burns in the presence of oxygen D- a new, more complex compound is formed
endothermic
a(n)_________ reaction is one in which heat is transferred from the surroundings to the reactants
rearranged
in a chemical reaction, atoms are_________, but they are not created or destroyed
C
which of the following represents the word equation magnesium + oxygen --> magnesium oxide? A- Ch4+O2-->CH4O2 B- MgO + O --> MgO2 C- 2Mg+O2-->2MgO D- 2CH4+O2-->2CH3OH