1) Which of the following methods can be used to obtain pure water from a mixture of sand, water and methanoic acid?
A. netralization with NaOHfoolowed by filtration
B. neutralization with NaOH followed by distillation
C. fractional distillation
D. filtration followed by distillation
2) How many atoms are present in 6.0g of magnesium?
[Mg = 24, NA = 6.02 x 1023 mol-1]
A. 1.20 x 1022
B. 2.41 x 1022
C. 1.51 x 1023
D. 3.02 x 1023
3) 50 cm3 of gas was collected over water at 10ºC and 765 mm Hg. Calculate the volume of the gas at s.t.p. if the saturated vapour pressure of water at 10ºC is 5mm Hg
A. 49.19 cm 3
B. 48.87 cm 3
C. 48.55 cm 3
D. 48.23 cm 3
4) An increase in the pressure exerted on gas at a constant temperature results in
A. a decrease in the number of effective collisions
B. a decrease in volume
C. an increase in the average intermolecular distance
D. an increase in volume
5) 2H2(g) + O2(g) → 2H2 O(g)
In the reaction above, what volume of hydrogen would be left over when 300 cm3 of oxygen and 1000 cm3 of hydrogen are exploded in a sealed tube?
A. 200 cm3
B. 400 cm3
C. 600 cm3
D. 700 cm3
6) l . Evaporation. ll. Sublimation. lll. Diffusion. IV. Brownian motion.
Which of the above can correctly be listed as evidences for the particulate nature of matter?
A. I and lll only
B. ll and lV only
C. l, ll and lll only
D. l, ll, lll and lV
7) If the elements X and Y have atomic numbers 11 and 17 respectively, what type of bond can they form?
8) A hydrogen atom which has lost an electron contains
A. one proton only
B. one neutron only
C. one proton and one neutron
D. one proton, one electron and one neutron
9) The electronic configuration of Mg2+ is
A. ls 22s 22P 63s23P2
10) Group VII elements are
B. good oxidizing agents
C. highly electropositive
D. electron donors