Chlorophyll obtained from given leaves of plant can be shown to be composed of more than one coloured component by the technique of

A. crystallization

B. hydrolysis

C. chromatography

D. sublimation

In countries where the temperature falls below 273K, salt is always sprinkled on the icy road in order to

A. lower the melting point of the ice

B. increase the density of the ice

C. make the ice impure

D. raise the melting point of the ice

2Na_(s) + 2H₂O_(l) → 2NaOH_(aq) + H_2(g)
From the equation above, calculate the mass of sodium hydroxide produced by 2.3g of sodium.
[H = 1, O = 16, Na = 23]

A. 0.40g

B. 0.80g

C. 4.00g

D. 8.00g

16.8 g of sodium hydrogen trioxocarbonate (IV) is completely decomposed by heat. Calculate the volume of carbon(IV) oxide given off s.t.p
[Na 23, C = 12, O = 16, H = 1, Molar volume of a gas at s.t.p = 22.4 dm³]

A. 22.40 dm³

B. 11.20 dm³

C. 2.24 dm³

D. 1.12 dm³

300 cm³ of gas has a pressure of 800 mmHg. If the pressure is reduced to 650 mmHg, find its volume

A. 243.75 cm³

B. 369.23 cm³

C. 738.46 cm³

D. 1733.36 cm³

Diffusion is slowest in solid particles than in particles of liquid and gases because

A. solid particles have more kinetic energy than the particles of liquid and gases

B. solid particles have less kinetic energy than the particles of liqiud and gases

C. solid particles have less restriction in their movement than liquid and gas particles

D. the particles in solids are far apart and the cohesive forces between them are negligible

The experiment that showed that atoms have tiny positively charged nucleus was first carried out by

A. Moseley

B. Rutherford

C. Millikan

D. Dalton

The atom of an element X is represented as _z^yX. The basic chemical properties of X depends on the value of

A. Y

B. Z

C. Y - Z

D. Z - Y

The diagram above represent the electron sub-level for

A. carbon

B. nitrogen

C. oxygen

D. flourine

In the periodic table, the electrical and thermal conductivities are properties of elements that

A. decrease across the period and increase down the group

B. increase across the period and decrease down the group

C. decrease across the period and down the group`

D. increase acrosss the period and down the group