The type of reaction ethyne mainly undergoes is

A. addition

B. carboxylation.

C. esterification

D. saponification

E. substitution

Which of the following laws is obeyed If at constant temperature, 200cm of hydrogen at 1.5 × 10m⁵Nm^-2pressure becomes 300cm³ at 1.0 × 10⁵Nm^-2 pressure?

A. Avogadro’s

B. Boyle’s

C. Charles’

D. Faraday’s

E. Graham’s

Chlorine atom forms Cl- by

A. donating lone pair of electrons

B. gaining an electron

C. losing an electron

D. sharing an electron

E. sharing a lone pair of electrons.

The most efficient absorber of ultraviolet radiation in the atmosphere is

A. CO₂

B. H₂

C. H₂O

D. 0₂

E. O₃

When dust particles collide randomly in a beam of Sunlight, the phenomenon observed is known as

A. Brownian movement.

B. Dialysis

C. Diffusion

D. Osmosis

E. Tyndall effect

\( ^{234}_{90}Th → ^{234}_{91}Pa + X \)
In the nuclear reaction above, X is

A. \( ^0_1e \)

B. \( ^0_{-1}e \)

C. \( ^4_2He \)

D. \( ^1_0n \)

E. \( ^1_1p\)

What is the colour of phenolphthalein indicator in a basic medium?

A. Blue

B. Colourless

C. Orange

D. Pink

E. Yellow

Which of the following will Increase the rate of reaction of Chips of a metal M as shown in the equation below?

M(s)+2HC1(aq) → MCI₂ (aq) + H₂(g)

A. Adding some distilled water

B. Decreasing the temperature

C. Diluting the hydrochloric acid

D. Grinding the metal into powder

E. Increasing the pressure

Which of the following is a component of the car exhaust?

A. Aluminium

B. Calcium

C. Iron

D. Zinc

E. Lead