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Practice test #4 - balancing , rxn types

 

 1. 

A solid produced by a chemical reaction in solution that separates from the solution is called
a.
a precipitate.
c.
a molecule.
b.
a reactant.
d.
the mass of the product.
 

 2. 

After the correct formula for a reactant in an equation has been written, the
a.
subscripts are adjusted to balance the equation.
b.
formula should not be changed.
c.
same formula must appear as the product.
d.
symbols in the formula must not appear on the product side of the equation.
 

 3. 

In writing an equation that produces hydrogen gas, the correct representation of hydrogen gas is
a.
H.
c.
H2.
b.
2H.
d.
OH.
 

 4. 

What is the small whole number that appears in front of a formula in a chemical equation?
a.
a subscript
c.
a ratio
b.
a superscript
d.
a coefficient
 

 5. 

According to the law of conservation of mass, the total mass of the reacting substances is
a.
always more than the total mass of the products.
b.
always less than the total mass of the products.
c.
sometimes more and sometimes less than the total mass of the products.
d.
always equal to the total mass of the products.
 

 6. 

A chemical equation is balanced when the
a.
coefficients of the reactants equal the coefficients of the products.
b.
same number of each kind of atom appears in the reactants and in the products.
c.
products and reactants are the same chemicals.
d.
subscripts of the reactants equal the subscripts of the products.
 

 7. 

Which word equation represents the reaction that produces water from hydrogen and oxygen?
a.
Water is produced from hydrogen and oxygen.
b.
Hydrogen plus oxygen yields water.
c.
H2 + O2 ® water.
d.
Water can be separated into hydrogen and oxygen.
 

 8. 

Which of the following is a formula equation for the formation of carbon dioxide from carbon and oxygen?
a.
Carbon plus oxygen yields carbon dioxide.
b.
C + O2 ® CO2
c.
CO2 ® C + O2
d.
2C + O ® CO2
 

 9. 

When the equation Fe3O4 + Al ® Al2O3 + Fe is correctly balanced, what is the coefficient of Fe?
a.
3
c.
6
b.
4
d.
9
 

 10. 

Which coefficients correctly balance the formula equation CaO + H2O ® Ca(OH)2?
a.
2, 1, 2
c.
1, 2, 1
b.
1, 2, 3
d.
1, 1, 1
 

 11. 

Which equation is NOT balanced?
a.
2H2 + O2 ® 2H2O
b.
4H2 + 2O2 ® 4H2O
c.
H2 + H2 + O2 ® H2O + H2O
d.
2H2 + O2 ® H2O
 

 12. 

In what kind of reaction do two or more substances combine to form a new compound?
a.
decomposition reaction
c.
double-replacement reaction
b.
ionic reaction
d.
synthesis reaction
 

 13. 

The equation AX ® A + X is the general equation for a
a.
synthesis reaction.
c.
combustion reaction.
b.
decomposition reaction.
d.
single-replacement reaction.
 

 14. 

The equation A + X ® AX is the general equation for a(n)
a.
combustion reaction.
c.
synthesis reaction.
b.
ionic reaction.
d.
double-replacement reaction.
 

 15. 

The equation A + BX ® AX + B is the general equation for a
a.
double-replacement reaction.
c.
single-replacement reaction.
b.
decomposition reaction.
d.
combustion reaction.
 

 16. 

The reaction Mg(s) + 2HCl(aq) ® H2(g) + MgCl2(aq) is a
a.
composition reaction.
c.
single-replacement reaction.
b.
decomposition reaction.
d.
double-replacement reaction.
 

 17. 

The reaction 2KClO3(s) ® 2KCl(s) + 3O2(g) is a(n)
a.
synthesis reaction.
c.
combustion reaction.
b.
decomposition reaction.
d.
ionic reaction.
 

 18. 

When potassium reacts with water, one product formed is
a.
hydrogen gas.
c.
potassium oxide.
b.
oxygen gas.
d.
salt.
 

 19. 

A precipitate forms in a double-replacement reaction when
a.
hydrogen gas reacts with a metal.
c.
water boils out of the solution.
b.
positive ions combine with negative ions.
d.
a gas escapes.
 

 20. 

What is the balanced equation when aluminum reacts with copper(II) sulfate?
a.
Al + Cu2S ® Al2S + Cu
c.
Al + CuSO4 ® AlSO4 + Cu
b.
2Al + 3CuSO4 ® Al2(SO4)3 + 3Cu
d.
2Al + Cu2SO4 ® Al2SO4 + 2Cu
 

 21. 

What is the name of a list of elements arranged according to the ease with which they undergo certain chemical reactions?
a.
reactivity list
c.
activity series
b.
reaction sequence
d.
periodic list
 

 22. 

An element in the activity series can replace any element
a.
in the periodic table.
c.
above it on the list.
b.
below it on the list.
d.
in its group.
 

 23. 

If metal X is lower than metal Y in the activity series, then metal X
a.
replaces ions of metal Y in a solution.
b.
loses electrons more readily than does metal Y.
c.
loses electrons less readily than does metal Y.
d.
forms positive ions more readily than does metal Y.
 

 24. 

Predict what happens when nickel is added to a solution of potassium chloride.
a.
No reaction occurs.
c.
Potassium nickel chloride forms.
b.
Nickel chloride forms.
d.
Hydrochloric acid forms.
 

 25. 

Magnesium bromide + chlorine yield
a.
Mg and BrCl.
c.
MgBrCl.
b.
MgCl and Br2.
d.
Mg(Cl)2 and Br2.
 

 26. 

Which reaction can be predicted from the activity series?
a.
2Cl ® Cl2
c.
2HCl + 2Na ® 2NaCl + H2
b.
HCl + NaOH ® NaCl + H2O
d.
Cl2 ® 2Cl
 



 
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