Chapter 8 Review
In an equation, the symbol for a substance in water solution is followed by
(aq)
Which coefficients correctly balance the formula equation CaO +H2O ---> Ca(OH)2?
1,1,1
Which coefficients correctly balance the formula equation NH4NO2(s) ---> N2(g) + H2O(l)?
1,1,2
When the equation Fe3O4 + Al ---> Al2O3 +Fe is correctly balanced, what is the coefficient of Fe?
9
The word equation solid carbon + oxygen gas ---> carbon dioxide gas + energy represents a chemical reaction because
CO2 has chemical properties that differ from those of C and O
In writing a chemical equations the produces hydrogen gas, the correct representation of hydrogen gas is
H2
How would oxygen be represented in the formula equation for the reaction of methane and oxygen to yield carbon dioxide and water?
O2
A chemical formula written over the arrow in a chemical equation signifies
a catalyst for the reaction
What is the small whole number that appears in front of a formula in a chemical equation?
a coefficient
When a solid produced by a chemical reaction separates from the solution it is called
a precipitate
The ability of an element to react is the element's
activity
What is the name of a list of elements arranged according to the ease with which the undergo certain chemical reactions?
activity series
After the first steps in writing an equation, the equation is balanced by
adjusting coefficients to the smallest whole-number ratio
According to the law of conservation of mass, the total mass of the reacting substances is
always equal to the total mass of the products
An element in the activity series can replace any element
below it on the list
Which observation does not indicate that a chemical reaction has occurred?
change in total mass of substances
To balance a chemical equation, it may be necessary to adjust the
coefficients
In what kind of reaction does a single compound produce two or more simpler substances?
decomposition reaction
The equation AX ---> A +X is the general equation for a
decomposition reaction
The reaction represented by the equation 2HgO(s) ---> 2Hg(l) + O2(g) is a(n)
decomposition reaction
In what kind of reaction does one element replace a similar element in a compound?
displacement reaction
In what kind of reaction do the ions of two compounds exchange places in aqueous solution to form two new compounds?
double-displacement reaction
The equation AX + BY ---> AY +BX is the general equation for a
double-displacement reaction
The reaction represented by the equation Pb(NO3)2(aq) + 2KI(aq) ---> PbI2(s) + 2KNO3(aq) is a
double-displacement reaction
The decomposition of a substance by an electric current is called
electrolysis
A chemical equation is balanced when the
same number of each kind of atom appears in the reactants and in the products
The equation A + BX ---> AX + B is the general equation for a
single-displacement reaction
The reaction represented by the equation Cl2(g) + 2KBr(aq) ---> 2KCl(aq) + Br2(l) is a(n)
single-displacement reaction
The reaction represented by the equation Mg(s) + 2HCl(aq) ---> H2(g) + MgCl2(aq) is a
single-displacement reaction
In what kind of reaction do two or more substances combine to form a new compound?
synthesis reaction
The equation A + X ---> AX is the general equation for a(n)
synthesis reaction
The reaction represented by the equation 2Mg(s) + O2(g) ---> 2MgO(s) is a
synthesis reaction
In a chemical reaction
the mass of the reactants equals the mass of the products
What can be predicted by using an activity series?
whether a certain chemical reaction will occur
Which equation is not balanced?
2H2 + O2 ---> H2O
