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

How many atoms are present in 6.0g of magnesium?
[Mg = 24, N_A = 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

50 cm³ of gas was collected over water at 10^oC and 765 mm Hg. Calculate the volume of the gas at s.t.p. if the saturated vapour pressure of water at 10 ^oC is 5mm Hg

A. 49.19 cm ³

B. 48.87 cm ³

C. 48.55 cm ³

D. 48.23 cm ³

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

2H_2(g) + O_2(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

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

If the elements X and Y have atomic numbers 11 and 17 respectively, what type of bond can they form?

A. Dative

B. Covalent

C. Ionic

D. Metallic

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

The electronic configuration of Mg ²⁺ is

A. ls ²2s ²2P ⁶3s²3P²

B. Is²2s²2P⁶

C. ls²2s²2p⁶3s²

D. ls²2s²2P⁴