Chemistry Final Exam (ch 8)
a
In a chemical reaction a. the mass of the reactants equals the mass of the products b. the mass of the products is greater than the mass of reactants c. the number of atoms in the reactants and products must change d. energy as heat must be added to the reactants
b
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
d
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
b
an element in the activity series can replace any element a. in the periodic table b. below it on the list c. above it on the list d. in this group
b
if a certain metal is placed in anionic solution containing another metal and no reaction occurs, then he metal originally in the solution is a. a halogen b. higher on the activity series c. not on the activity series d. unreactive
c
in the equation 2Al(s) +3Fe(NO3)2(aq)->3Fe(s) + 2Al(NO3)3(aq) iron has been replaced by a. nitrate b. water c. aluminum d. nitrogen
b
in what kind of reaction do the ions of two compounds exchange places in aqueous solution to form two new compounds a. synthesis reaction b. double displacement reaction c. decomposition reaction d. combustion reaction
d
in what kind of reaction do two or more substances combine to form a new compound a. decomposition reaction b. ionic reaction c. double-displacement reaction d. synthesis reaction
a
in what kind of reaction does a single compound produce two or more simpler substances a. decomposition reaction b. synthesis reaction c. single displacement reaction d. ionic reaction
a
in what kind of reaction does one element replace a similar element in a compound a. displacement reaction b. combustion c. decomposition reaction d. ionic reaction
c
in writing a chemical equation that produces hydrogen gas, the correct representation of hydrogen gas is a. H b. 2H c. H2 d. OH
b
the ability of an element to react is the element's a. valence b. activity c. stability d. electronegativity
a
the decomposition of a substance by an electric current is called a. electrolysis b. conduction c. ionization d. transformation
c
the equation A + X->AX is the general equation for a a. combustion reaction b. ionic reaction c. synthesis reaction d. double-displacement reaction
c
the equation A+BX->AX+B is the general equation for a a. double displacement reaction b. decomposition reaction c. single displacement reaction d. combustion reaction
d
the equation AX+BY->AY+BX is the general equation for a a. synthesis reaction b. decomposition reaction c. single-displacement reaction d. double-displacement reaction
b
the equation AX->A+X is the general equation for a a. synthesis reaction b. decomposition reaction c. combustion reaction d. single-displacement reaction
d
the reaction represented by the equation 2HgO(s)->2Hg(l)+O2(g) is a a. single displacement reaction b. synthesis reaction c. combustion reaction d. decomposition reaction
b
the reaction represented by the equation 2KClO2(s)-> 2KCl(s) +3O2(g) is a a. synthesis reaction b. decomposition reaction c. combustion reaction d. ionic reaction
a
the reaction represented by the equation 2Mg(s) +O2(g) -> 2MgO(s) is a a. synthesis reaction b. decomposition reaction c. single displacement reaction d. double displacement reaction
c
the reaction represented by the equation Cl2(g)+2KBr(aq) -> 2KCl(aq)+Br2(l) us ab a, synthesis reaction b. decomposition reaction c. single displacement reaction d. combustion reaction
c
the reaction represented by the equation Mg(s)_2HCl(aq)-> H2(g) +MgCl2(aq) is a a. composition reaction b. decomposition reaction c. single displacement reaction d. double displacement reaction
a
the reaction represented by the equation Pb(NO3)2(aq)+2KI(aq)->PbI2(s) + 2KNO2(aq) is a a. double displacement reaction b. synthesis reaction c. decomposition reaction d. combustion reaction
a
what can be predicted by using an activity series a. whether a certain chemical reaction will occur b. the amount of energy released by a chemical reaction c. the electronegativity values of elements d. the melting points of elements
c
what is the name of a list of elements arranged according to the ease with which they undergo certain chemical reactions a. reactivity list b. reaction sequence c. activity series d. periodic list
d
what is the small whole number that appears in front of a formula in a chemical equation a. a subscript b. a superscript c. a ratio d. a coefficient
a
when a solid produced by a chemical reaction separates from the solution it is called a. a precipitate b. a reactant c. a molecule d. the mass of the product
d
which equation is not balanced? a. 2H2+O2-> 2H2O b. 4H2+2O2->4H2O c. H2+H2+O2->H2O+H20 d. 2H2 +O2->H2O
d
which observation does not indicate that a chemical reaction has occurred a. formation of a precipitate b. production of a gas c. evolution of heat and light d. change in total mass of substances