CHAPTER 8- Practice Exercise
Albert Kweyete
1. Use the following given atomic radii to estimate the bond lengths between
elements in molecules.
molecule
bond
bond length (A0)
atomic radii(A0)
PBr3
P - Br
P= 1.10
NaCl
Na-Cl
H=0.37
CH4
C-H
Cl=0.99
CH3OH
C-O
C=0.77
O-H
O=0.7
Cl2
Cl-Cl
Na=1.86
N=0.75
Br= 1.14
2. Using atomic radii table predict which will have greater (circle one) bond length.
a) C-H , O-H
b) H-Cl , H-Br
c) P-Cl , C-N
d) P-Cl , P-Br
e) N-H , S-H
f) N-C , N-O
3. Refering to periodic table, arrange the following atoms in order of increasing or
decreasing.
a) increasing atomic size: Na, F, P, Ca
b) increasing first ionization energy: Li, Na, k, Rb, Cs
c) increasing second ionization energy: K, Al, Mg, C
d) decreasing metallic properties: Cl, K, P, Mg
e) increasing nonmetallic properties: Cu, Sr, I, N
f) increasing electron affinity : N, O, Be, K
g) decreasing electronegativity: Cl, I, S, O
h) increasing electropositivity: S, C, Mg, Al
4. Write the chemical formula for the following oxides.
a) aluminum oxide
b) sodium peroxide
d) zinc peroxide
e) phosphorous pentoxide
c) sodium superoxide
f) manganese dioxide
5. Identify the following oxides as acidic(non-metallic), basic(metallic) , or
amphoteric oxides.
a) ZnO
b) Na2O
c) P4O6
d) CaO
e) SO3
f) Al2O3
g) NO
h) CoO
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6. Write a balance equations that predict the reactions of solid zinc with the
followings: a) HCl
b) H2
c) H2O
d) Cl2
e) O2
f) S
g) FeSO4 h) conc. HNO3
i) conc. H2SO4
j) dil. H2SO4
7. Write the balanced chemical equations for the reactions of the followings ;
a) SO3 + KOH 
b) P4O6 + H2O 
c) CO2 + NaOH 
d) CuO + HCl 
e) K2O + H2O 
f) BaO + H2O 
g) ZnO + HCl 
h) Mg + dil.H2SO4 
i) Al + Cl2 
j) Ca + H2 
k) Ba + O2 
l) Na + O2 
heat
m) N2O3 + H2O 
n) H2O2
o) K + S 
p) H2 + Br2 

8. Complete and balanced the following reactions.
a) K + .....  KOH + H2
b) SO2+1/2O2+H2O .......
c) Ca + .....  CaO
d) Fe + Cl2  FeCl3 + ......
e) .....+ H2O  H3PO4
f) Na + O2 ........
g) SO2+NaOH Na2SO4 +....
h) HCl + HClO  Cl2 +....
i) Mg + H2O  MgO + ....
j) Ca + H2O  Ca(OH)2 +.....
9. Predict whether each of the following oxide is ionic or Covalent molecular.
a) SiO2
b) P2O5
c) Cr2O3 d) BeO f) CoO
10. Consider the following elements: Cl, N, Mg, S . Identify :
a) largest in size
b) most metallic c) highest in ionization energy
d) highest in electronegativity
e) highest electron affinity
f) most reactive with water
g) with water gives basic oxide
h) has 7 valence electrons
i) has an ionic forms with charge of -2
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