3.1 Balance:
a) Cu+O2>CuO
b) Fe+Cl2>FeCl3
c) C+Br2>CBr4
Solutions: Copy bal.expr. into "unbalanced equation" edit field and
calculate.
3.2 Balance:
a) Zn+HCl>ZnCl2+H2
a) Al+HCl>AlCl3+H2
c) Sn+HCl>SnCl4+H2
Solutions: Copy bal.expr. into "unbalanced equation" edit field and
calculate.
3.3 Alkane-oxygen combustion's generally forms CO2 and water. Balance:
a) CH4+O2>CO2+H2O
b) C2H6+O2>CO2+H2O
c) C3H8+O2>CO2+H2O
Solutions: Copy bal.expr. into "unbalanced equation" edit field and
calculate.
3.4 Balance:
a) Na2CO3+HNO3>NaNO3+H2O+CO2
b) KClO3+S+H2O>Cl2+K2SO4+H2SO4
c) FeS2+O2>Fe3O4+SO2
d) Al(OH)3+H2SO4>Al2(SO4)3+H2O
e) KBr+MnO2+H2SO4>Br2+MnBr2+KHSO4+H2O
f) Na3SbS4+HCl>Sb2S5+H2S+NaCl
g) Cu+HNO3>Cu(NO3)2+NO+H2O
h) Ca3P2+H2O>Ca(OH)2+PH3
i) FeSO4+KMnO4+H2SO4>Fe2(SO4)3+MnSO4+K2SO4+H2O
Solutions: Copy bal.expr. into "unbalanced equation" edit field and
calculate.
Balance - Stoichiometry
3.5 8 grams of C5H12 reacts with oxygen.
Balance:
C5H12+O2>CO2+H2O and determine:
a) How many grams of CO2 was formed in the reaction?
b) How many grams of H2O was formed in the reaction?
c) How many grams of O2 was used during the reaction?
Solutions:8gC5H12+O2>CO2+H2O Copy argumented bal.expr. into
"unbalanced
equation" edit field and calculate.
3.6 A piece of metallic iron (3g) was dissolved in conc.HCl (6 grams of
100%
HCl). The reaction formed H2 and FeCl2.
Balance: Fe+HCl>FeCl2+H2 and determine
a) amount of formed FeCl2
b) amount of formed H2
Solutions: 3gFe+6gHCl>FeCl2+H2 Copy argumented bal.expr. into
"unbalanced
equation" edit field and calculate.
3.7 Balance: N2+H2>NH3 and determine how many grams of nitrogen and
hydrogen
used in a reaction forming 15.0 grams of NH3 .
Solution:N2+H2>15gNH3 Copy argumented bal.expr. into "unbalanced
equation"
edit field and calculate.
3.8 Balance following heated mixture reaction:
As2S3+NaNO3+Na2CO3>Na3AsO4+Na2SO4+NaNO2+CO2
Determine:
a) Amount of As2S3, NaNO3 and Na2CO3 used forming 23.0 grams of Na3AsO4
?
b) How much CO2 will be formed if the "raw material" for the reaction
was
10.0 grams As2S3, 75.0 grams NaNO3 and 37.0 grams of Na2CO3 ?
Solutions:Modify balance expr. and calculate
a) As2S3+NaNO3+Na2CO3>23gNa3AsO4+Na2SO4+NaNO2+CO2
b) 10gAs2S3+75gNaNO3+37gNa2CO3>Na3AsO4+Na2SO4+NaNO2+CO2
3.9 Balance:
Na2CO3+HNO3>NaNO3+H2O+CO2
Determine:
a) How much carbon dioxide will be formed using 13.4 grams of sodium in
Na2CO3
?
b) How much H2O will be formed if Na2CO3 contains 3.4 grams of carbon
and
HNO3 contains 18.8 grams of nitrogen?
c) How many moles of NaNO3 will be formed if CO2 contains 12.3 grams of
carbon.
Solutions:Modify balance expr.:
a)13.4gNa,Na2CO3+HNO3>NaNO3+H2O+CO2
b)3.4gC,Na2CO3+18.8gN,HNO3>NaNO3+H2O+CO2
c)Na2CO3+HNO3>NaNO3+H2O+12,3gC,CO2
3.10 Metallic iron may be produced by heating a mixture of Fe2O3 and
carbon.
Balance:
Fe2O3+C>Fe+CO2
and determine moles of:
a) Fe2O3 in a reaction forming 1000 grams of Fe.
b) Fe in a reaction using 200 grams of C.
c) CO2 in a reaction forming 12.8 moles Fe.
Solutions:Modify balance expr.
a) Fe2O3+C>1000gFe+CO2
b) Fe2O3+200gC>Fe+CO2
c) Fe2O3+C>12.8mFe+CO2
3.11 FeS2 and O2 reacts forming Fe3O4 and SO2. Balance:
FeS2+O2>Fe3O4+SO2
Determine the amount of formed SO2 and Fe3O4 using 12.0 grams of Fe in
FeS2
and 1.5 moles of O in O2?.
Solution:Modify balance expr.
12gFe,FeS2+1.5mO,O2>Fe3O4+SO2
3.12 KClO3 added HCl forms Cl2
Balance:
KClO3+HCl>H2O+KCl+Cl2
Determine:
a)Amount of KClO3 used in a reaction forming 2 grams of Cl2.
b)A compound (KClO3) contains 4 g oxygen. How much Cl2 will be formed
adding
0.04 moles of HCl ?
Solutions:Modify balance expr.
a) KClO3+HCl>H2O+KCl+3gCl2
b) 4gO2,KClO3+0.04mHCl>H2O+KCl+Cl2
3.14 1 kg octane reacts with oxygen. Determine vol. O2 (NTP) used in
this
reaction.
Solution:Modify balance expr.
Step 1: 1000gC8H18 + O2 > CO2 +H2O
Step 2: Calculate O2 -vol. using V=nRT/p.
(n) moles of oxygen (calculated in Step 1):
(gass const.) R=0.082liter*atm/(Kelvin*mol)
(temp.) T=273.15Kelvin
(pressure) p=1atm.
3.15 10.99 grams of a compund containing C, H and O reacts with O2
forming
H2O and 21.0 grams of CO2. What's the empiric formula for the compund?
Solution:Find the answer by observing the effect of varying the values
of
X,Y and Z in following argumented (21g) balance expression:
CXHYOZ + O2 > 21gCO2 + H2O