chemistry test
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 NH4 NO2 (s)---> N2 (g)+ H2 O (L)?
1,1,2
what are the coefficients that will balance the skeleton equation below?N2 + H2 ----> NH3
1,3,2
When the equation Fe3O4 + Al ---> Al2O3+ Fe is correctly balanced, what is the coefficient of Fe?
9
Which of the following is a formula equation for the formation of carbon dioxide from carbon and oxygen?
C + O2 ---> CO2
The complete combustion of which of the following substances produces carbon dioxide and water?
C8H18
How would oxygen be represented in the formula equation for the reaction of methane and oxygen yield carbon dioxide and water?
CO2 ---> C + O2
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
A double displacement reaction takes place when aqueous cobalt (II) chloride reacts with aqueous lithium hydroxide. One of the products of this reason is
Co(OH)3
To balance a chemical equation, it may be necessary to adjust the
Coefficients
What is the small whole number that appears in front of a formula in a chemical equation ?
Coefficients
In what kind of reaction does a single compound produce two or more simpler substances?
Decomposition reaction
In writing a chemical equation that produces hydrogen gas, the correct representation of hydrogen gas is
H subscript 2
In the word equation, sodium oxide + water --> sodium hydroxide, the formula for sodium hydroxide is represented by
NaOH
In what kind of reaction do two or more substances combine to form a new compound?
Synthesis reaction
The complete balanced equation for the reaction between zinc hydroxide and acetic acid is
Zn(OH)2+ 2CH3COOH---> Zn(CH3COO) + 2H2O
A chemical formula written over the arrow in a chemical equation signifies
a catalyst for the reaction
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
when heated, a metal carbonate decomposes into a metal oxide and
carbon dioxide
which observation does not indicate that a chemical reaction has occurred?
change in total mass of substances
the equation 2C3H7OH+9O2-> 6CO2+8H2O, is an example of which type of reaction
combustion 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
decomposition reaction
The reaction represented by the equation 2kclo3(s)→2kcl(s)+3o2(g) is a
decomposition 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
Oxides of active metals, such as CaO, react with water to produce
metal hydroxides
In one type of synthesis reaction, an element combines with oxygen to yield an
oxide
In a combustion reaction, one of the reactants is
oxygen
An active metal and a halogen react to form a
salt
A chemical equation is balanced when the
same number of each kind of atom appears in the reactants 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
single displacement reaction
The equation A + X ---> is the general equation for a
synthesis reaction
The reaction represented by the equation 2Mg(s) + O2(g) --> 2MgO is a
synthesis reaction
in a chemical reaction
the mass of reactants equal the mass of the products
When the following equation is balanced, what is the coefficient for HCl? Mg(s) + HCl(aq) -->MgCl2(aq) +H2(g)
2
Which equation is not balanced?
2H2+ O2--->H2O
