Physical Science Test 7A
 
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Physical Science Test 7A

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

 1. 

The substances that undergo change in a chemical reaction are called
a.
reactants.
c.
coefficients.
b.
products.
d.
elements.
 

 2. 

Hydrochloric acid, HCl, is added to solid NaOH. After the reaction is complete, NaCl dissolved in water remains. What are the products of this chemical reaction?
a.
NaOH and HCl
c.
HCl and NaCl
b.
NaOH and H2O
d.
NaCl and H2O
 

 3. 

Which of the following does NOT state what the arrow means in a chemical equation?
a.
forms
c.
conserves
b.
produces
d.
yields
 

 4. 

Which of the following does NOT show the law of conservation of mass?
a.
24 g of Mg burn in 32 g O2 to produce 56 g of MgO.
b.
24 mL of Mg burn in 32 mL O2 to produce 56 mL of MgO.
c.
2 atoms of Mg react with 1 molecule of O2 to produce 2 units of MgO.
d.
1 atom of Mg reacts with 1 atom of O to produce a unit of MgO that contains 2 atoms.
 

 5. 

Which of the following is a chemical equation that accurately represents what happens when sulfur and oxygen react to form sulfur trioxide?
a.
Sulfur and oxygen react to form sulfur trioxide.
b.
S and O2 produce SO3.
c.
S + O2 ® SO3
d.
2S + 3O2 ® 2SO3
 

 6. 

Which of the following is a balanced chemical equation for the synthesis of NaBr from Na and Br2?
a.
Na + Br2 ® NaBr
b.
2Na + Br2 ® NaBr
c.
Na + Br2 ® 2NaBr
d.
2Na + Br2 ® 2NaBr
 

 7. 

Methane, CH4, burns in oxygen gas to form water and carbon dioxide. What is the correct balanced chemical equation for this reaction?
a.
CH4 + O ® H2O + CO2
b.
CH4 + 4O ® 2H2O + CO2
c.
CH4 + O2 ® H2O + CO2
d.
CH4 + 2O2 ® 2H2O + CO2
 

 8. 

How many atoms are present in 3 moles of chromium?
a.
6.02 ´ 1023 atoms
c.
1.80 ´ 1024 atoms
b.
1.80 ´ 1023 atoms
d.
52.0 atoms
 

 9. 

How many grams of CO2 are in 2.1 mol of the compound?
a.
21.0 g
c.
66.0 g
b.
44.0 g
d.
92.4 g
 

 10. 

How many moles of He are in 16 g of the element?
a.
1.0 mol
c.
8.0 mol
b.
4.0 mol
d.
16 mol
 

 11. 

An industrial process makes calcium oxide by decomposing calcium carbonate. Which of the following is NOT needed to calculate the mass of calcium oxide that can be produced from 4.7 kg of calcium carbonate?
a.
the balanced chemical equation
b.
molar masses of the reactants
c.
molar masses of the product
d.
the volume of the unknown mass
 

 12. 

The coefficients in a balanced chemical equation always can express the ratio of
a.
moles of reactants and products.
b.
volume of reactants and products.
c.
atoms of reactants and products.
d.
mass of reactants and products.
 

 13. 

When magnesium carbonate, MgCO2, reacts with nitric acid, HNO3, magnesium nitrate and carbonic acid form. Carbonic acid then breaks down into water and carbon dioxide. Which two types of reactions take place in this process?
a.
synthesis and decomposition
b.
single-replacement and combustion
c.
double-replacement and decomposition
d.
double-replacement and combustion
 

 14. 

Which of the following is NOT always true about a synthesis reaction?
a.
One product is formed.
b.
There is only one reactant.
c.
The general formula is A + B ® C.
d.
A reactant might be a compound, or it might be an element.
 

 15. 

Which of the following takes place during a redox reaction?
a.
Electrons are gained only.
b.
Electrons are lost only.
c.
Electrons are both gained and lost.
d.
Electrons are neither gained nor lost.
 

 16. 

In a chemical reaction, an iron atom became the ion Fe2+. What happened to the iron atom?
a.
It lost electrons and was oxidized.
b.
It lost electrons and was reduced.
c.
It gained electrons and was oxidized.
d.
It gained electrons and was reduced.
 

 17. 

In a compound, chemical energy is contained in the
a.
nuclei of the atoms.
c.
bonds.
b.
unbonded electrons.
d.
movement of the electrons.
 

 18. 

Which of the following statements is true about what happens during a chemical reaction?
a.
Bonds of the reactants are broken, and bonds of the products are formed.
b.
Bonds of the reactants are formed, and bonds of the products are broken.
c.
The bonds of both the reactants and the products are broken.
d.
The bonds of both the reactants and the products are formed.
 

 19. 

In terms of energy, how would you classify the following chemical reaction?
2Cu + O2 ® 2CuO + 315 kJ
a.
endothermic
b.
exothermic
c.
both endothermic and exothermic
d.
neither endothermic nor exothermic
 

 20. 

For the chemical reaction C2H6 + 137 kJ ® C2H4 + H2, the chemical energy of the
a.
reactant is greater than the chemical energy of the products.
b.
products is greater than the chemical energy of the reactant.
c.
reactant and the chemical energy of the products are equal.
d.
reaction is conserved.
 

 21. 

The total amount of energy before and after a chemical reaction is the same. Thus, energy is
a.
created.
c.
conserved.
b.
destroyed.
d.
the same as mass.
 

 22. 

For the chemical reaction H2 + CO2 ® H2O + CO, the energy contained in the reactants is 352 kJ, and the energy contained in the products is 394 kJ, assuming 1 mol of each substance is present. Which of the following statements is true?
a.
42 kJ is released, and the reaction is exothermic.
b.
42 kJ is released, and the reaction is endothermic.
c.
42 kJ is absorbed, and the reaction is exothermic.
d.
42 kJ is absorbed, and the reaction is endothermic.
 

 23. 

Reaction rates do NOT tell you how fast
a.
reactants are being consumed.
b.
products are being formed.
c.
substances are changing state.
d.
energy is being absorbed or released.
 

 24. 

In general, if the temperature of a chemical reaction is increased, the reaction rate
a.
increases.
c.
remains the same.
b.
decreases.
d.
cannot be predicted.
 

 25. 

A log is burning in a fireplace. If the amount of oxygen reaching the log is decreased, which of the following statements is true?
a.
The reaction rate increases.
b.
The reaction rate decreases.
c.
The reaction rate remains the same.
d.
The reaction rate depends only on the temperature.
 

 26. 

When the forward and reverse paths of a change occur at the same rate,
a.
the system is conserved.
b.
the system is in equilibrium.
c.
the change must be physical.
d.
the change must be chemical.
 

 27. 

The equation 2NO2 « N2O4 shows a system
a.
in chemical equilibrium.
b.
in physical equilibrium.
c.
that does not reach equilibrium.
d.
that does not change.
 

 28. 

What happens to the reaction 2NO2 «N2O4+ 57.2 kJ when the temperature of the reaction is increased?
a.
More reactant is formed.
b.
More product is formed.
c.
No change occurs in the amounts of reactant and product present.
d.
The effect depends on whether or not a catalyst is present.
 

 29. 

The reaction H2CO3 + H2O « H3O+ + HCO3 takes place in water. What happens to the equilibrium when the pressure is increased?
a.
It favors formation of reactants.
b.
It favors formation of products.
c.
It does not change.
d.
It is conserved.
 
 
pstest7a_files/i0310000.jpg

Figure 7-1
 

 30. 

The reaction in Figure 7-1 shows the formation of ammonia from nitrogen and hydrogen in the Haber process. What will be the effect on the equilibrium if the temperature is increased and some of the ammonia is removed from the system?
a.
More ammonia will definitely form.
b.
More reactants will definitely form.
c.
The changes definitely will have no overall effect on the reaction.
d.
Any effect will depend on the amount of change of temperature and concentration.
 



 
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