Practice set for exam-3
Q. Balance the following equations:
______C3H8 + ______O2
 _____ CO2 + _____H2O
______ NH3 + ______ O2
 _____ NO + _____ H2O
______ H2 + _____ Br2 
_____ HBr
______ Al + ______ Fe3O4  _____ Al2O3 + _____Fe
______ SO2 + _____ O2  _____ SO3
 _____ BaSO4 + _____ KCl
______ K2SO4 + ______ BaCl2
______ KClO3 
_____ KCl + _____ O2
______ AgNO3 + ______ BaCl2
 _____ Ba(NO3)2 + _____ AgCl
Ans. Balance the following reaction
______C3H8 + ___5___O2
 ___3__ CO2 + __4___H2O
___4___ NH3 + ___5___ O2
______ H2 + _____ Br2 
 __4___ NO + ___6__ H2O
___2__ HBr
__8____ Al + ___3___ Fe3O4  ___4__ Al2O3 + __9___Fe
___2___ SO2 + _____ O2  __2___ SO3
______ K2SO4 + ______ BaCl2
 _____ BaSO4 + __2___ KCl
___2___ KClO3 
___2__ KCl + ___3__ O2
___2___ AgNO3 + ______ BaCl2
 _____ Ba(NO3)2 + __2___ AgCl
Q. During photosynthesis, plants convert carbon dioxide and water into glucose C6
H12O6 according to the reaction:
6 CO2 (g) + 6 H2O(l)
=>
C6 H12O6(g)
+
6 O2 (g)
Suppose that a particular plant consumes37.8g of CO2 in one week. Assuming that
there is more than enough water present to react with all of the CO2, What mass of
glucose (in grams) can the plant synthesis from the CO2 ? 25.8g
Q|.
.
Zinc metal reacts with aqueous hydrochloric acid to give an aqueous solution of zinc chloride
and
hydrogen gas. Select the correct balanced chemical equation for this reaction.
a. Zn(s) + HCl(aq)  3ZnCl(aq) + H2(g)
b. Zn(s) + HCl(g)  ZnCl(aq) + H(g)
c. Zn(s) + 2HCl(aq)  ZnCl2(aq) + H2(g)
d. 2Zn(s) + 4HCl(aq)  2ZnCl2(aq) + H2(g)
e. 2Zn(s) + HCl(aq)  2ZnCl2(aq) + H2(g)
Answer: c
. Select the correct balanced chemical equation for the reaction below.
C6H14 + O2  CO2 + H2O
a. 2C6H14 + 9O2  12CO2 + 7H2O
b. 2C6H14 + 19O2  12CO2 + 14H2O
c. 2C6H14 + 12O2  12CO2 + 14H2O
d. 3C6H14 + O2  18CO2 + 22H2O
e. C6H14 + O2  CO2 + H2O
Answer: b
Given: 3H2(g) + N2(g)  2NH3(g)
If the reaction starts with 0.500 mol of H2, how many atoms of hydrogen in the compound NH3
would you expect to make?
a. 3.01  1023 atoms
b. 6.02  1023 atoms
c. 12.04  1023 atoms
d. 1 atom
e. 6 atoms
Answer: b
What is the coefficient of H2O when the following equation is properly balanced with the
smallest set of whole numbers?
___ Na + ___ H2O  ___ NaOH + ___ H2
a. 3
b. 4
c. 6
d. 12
e. 24
Answer: d
You are given the balanced chemical equation:
4AsF3 + 3C2Cl6  4AsCl3 + 3C2Cl2F4.
If 1.3618 moles of AsF3 are allowed to react with 1.000 mole of C2Cl6, what would be the
theoretical yield of AsCl3, in moles?
a. 0.3618 moles
b. 0.7343 moles
c. 0.7500 moles
d. 1.3333 moles
e. 1.3618 moles
Answer: d
Q.Q.Ammonia reacts with diatomic oxygen to form nitric oxide and water vapor:
4NH3 + 5O2  4NO + 6H2O
When 40.0 g NH3 and 50.0 g O2 are allowed to react, which is the limiting reagent?
a.
b.
c.
d.
e.
NH3
O2
NO
H2O
there is no limiting reagent
Answer: b
Q. Chlorine gas can be made from the reaction of manganese dioxide with hydrochloric acid.
Which is the limiting reagent when 28 g of MnO2 are mixed with 42 g of HCl?
MnO2(s) + 4HCl(aq)  MnCl2(aq) + 2H2O(l) + Cl2(g)
a.
b.
c.
d.
e.
MnO2
HCl
MnCl2
H2O
Cl2
Answer: b
Q.For the given process:
TiCl4(g) + 2Mg(l)  2MgCl2(l) + Ti(s)
If 1 mole of magnesium is reacted with an excess of TiCl4 gas, how many moles of titanium
(Ti) can be produced?
Answer: 0.5 moles
.
Q. Ammonia reacts with diatomic oxygen to form nitric oxide and water vapor:
4NH3 + 5O2  4NO + 6H2O
When 20.0 g NH3 and 50.0 g O2 are allowed to react, which is the limiting reagent?
Answer: NH3
The questions below will help you to write the product ( formula of the compound correctly due to the
double displacement and single displacement reactions)
Q.The formula for the compound formed from the barium ion and SO32- is ______.
Answer: BaSO3
Q. What is the formula of the compound formed from Cr3+ and H2PO4-? ______
Answer: Cr(H2PO4)3
. Q.What is the formula of the compound formed from the calcium ion and HCO 3-? ______
Answer: Ca(HCO3)2
Q.What is the name of the following compound: (NH4)2SO4? _______
Answer: ammonium sulfate
Q.The activity series of metals is
Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs
This means that cadmium will displace aluminum from an aqueous solution of aluminum
sulfate.
___
Answer: False
Q.What are the likely products of the reaction of copper oxide reacts nitric acid?
Hint : double displacement reaction
Answer: Cu(NO3)2 and H2O + heat
Q. Complete and balance the equations for these reactions:
1) Potassium phosphate and barium chloride
2) Hydrochloric acid and nickel carbonate
3) Ammonium chloride and sodium nitrate
Q. All orbitals with the same value of the principal quantum number are said to belong
to the same
a.
b.
shell.
subshell.
c.
group.
d.
period.
e.
class.
Answer: a
Q.All orbitals with the same value of the principal quantum number and the
secondary quantum
number are said to belong to the same
a. shell.
b. subshell.
c. group.
d. period.
e. class.
Answer: b
Q. The notation for the subshell with n = 5 and l = 3 is
a. 5d subshell.
b. 5p subshell.
c. 5f subshell.
d. 5g subshell.
e. 5s subshell.
Answer: c
Q. The notation for the subshell with n = 4 and l = 2 is
a.
4d subshell.
b.
4p subshell.
c. 4f subshell.
d.
e.
4s subshell.
There is no subshell fitting this description.
Answer: a
Q.The notation for the subshell with n = 3 and l = 3 is
a. 3d subshell.
b. 3f subshell.
c. 3p subshell.
d. 3s subshell.
e. There is no subshell fitting this description.
Answer: e
Q.How many orbitals are in the n = 2 shell.
a.
b.
c.
d.
e.
1
2
3
4
8
Answer: d
Q.The Pauli principle states that
a.
an electron in an atom can move to another energy level.
b.
the energy of an electron has a specific quantum number.
c.
the electron trapped in an atom has particle characteristics.
d.no two electrons in the same atom can have all their quantum numbers the
same.
e.
an orbital can hold as many electrons as possible.
Answer: d
Q.What is the maximum number of electrons that can fill all the orbitals of a f subshell?
a. 6
b. 8
c. 10
d. 12
e. 14
Answer: e
. What is the maximum number of electrons that can fill all the orbitals of a d subshell?
a. 6
b. 8
c. 10
d. 12
e. 14
Answer: c
Q.What is the maximum number of electrons that can fill all the orbitals of a p subshell?
a. 2
b. 3
c. 4
d. 6
e. 10
Answer: d
Q.The maximum number of electrons required to fill all the energy levels for a shell
having principal quantum number n is
a.
b.
c.
d.
e.
n
n+1
2n
n2
2n2
Answer: e
Q. Give the electronic configuration for the valence electrons in these elements.
a) B
b) N C) Na d) Cl
Q. Write the abbreviated electronic configurations for the following elements:
1) K
2) Sr 3) Te
4) Ba
5) Br
6) Ca