I. Write the reference number of the correct answer.

QUESTION 01

Which nucleus of the atoms (1) to (4) has just one neutron?

(1) \(\ce{^1H}\)

(2) \(\ce{^4He}\)

(3) \(\ce{^6Li}\)

(4) \(\ce{^5Be}\)

QUESTION 02

Which of the atoms (1) to (4) has the smallest atomic radius?

(1) \(\ce{Si}\)

(2) \(\ce{Ge}\)

(3) \(\ce{Sn}\)

(4) \(\ce{Pb}\)

QUESTION 03

Which of the underlined atoms in the molecules (1) to (4) has just one lone pair of electrons?

(1)  \(\ce{\underline {B}F3}\)

(2) \(\ce{\underline {C}O2}\)

(3) \(\ce{\underline {N}H3}\)

(4) \(\ce{H\underline {F}}\)

QUESTION 04

Which of the substances (1) to (4) has the lowest boiling point?

(1) \(\ce{He}\)

(2) \(\ce{N2}\)

(3) \(\ce{O2}\)

(4) \(\ce{Kr}\)

QUESTION 05

Which of the descriptions (1) to (4) is correct for copper and zinc?

(1) Both form divalent cation.

(2) Both dissolve in hydrochloric acid.

(3) Both sulfides dissolve in concentrated hydrochloric acid.

(4) Copper is more easily oxidized than zinc.

QUESTION 06

Which of reactions described in (1) to (4) is an oxidation-reduction reaction?

(1) \(\ce{CaCO3 + 2 HCl -> CaCl2 + CO2 + H2O}\)

(2) \(\ce{P4O10 + 6H2O ➔ 4H3PO4}\)

(3) \(\ce{Al(OH)3 + NaOH ➔ Na[Al(OH)4]}\)

(4) \(\ce{I2 + 2Na2S2O3 ➔ 2Nal + Na2S4O6}\)

QUESTION 07

Which of the descriptions (1) to (4) is not correct to describe a phenomenon that can be observed when a catalyst is introduced in a chemical reaction?

(1) The activation energy of a chemical reaction with a catalyst is lower than that of a chemical reaction without a catalyst.

(2) The heat of reaction of a chemical reaction with a catalyst is lower than that of a reaction without a catalyst.

(3) The rate of forward reaction of a chemical reaction with a catalyst is higher than that of a reaction without a catalyst.

(4) The rate of reverse reaction of a chemical reaction with a catalyst is higher than that of a reaction without a catalyst.