If 100 atoms of element X contains 70 atoms of⁹X and 30 atoms of¹¹X, calculate the relative atomic mass of X

• A. 9.6
• B. 10.6
• C. 11.6
• D. 20.0

The complete oxidation of proan -1-ol yields

• A) CH₃CH₂CHO
• B) CH₃COCH₃
• C) CH₃COOH₃
• D) CH₃CH₂COOH

The shapes of CO₂, H₂O and CH₄ respectively are

• A) bent, linear and tetrahedral
• B) bent, tetrahedral and linear
• C) linear, bent and tetrahedral
• D) tetrahedral, linear and bent

Aluminium hydroxide is used in the dyeing industry as a

• A. Salt
• B. Dye
• C. Mordant
• D. Dispersant

Which of the following statements about sodium is not true?

• A. Na⁺ is smaller in size than Na
• B. Na is smaller in size than Na⁺
• C. Na⁺ has fewer electrons than Na
• D. The effective nuclear charge in Na⁺ is greater than in Na

Which of the following statements about fine chemical is correct? It

• A. is injurious to health
• B. has low degree of purity
• C. is produced in relatively small amount
• D. can be stored for a long time

(a) (i) Define the term Avogadro's number.

(ii) If 2.30 g of an oxide of nitrogen, x, contains 3.01 x 10\(^{22}\) molecules, calculate the molar mass of x.

(iii) Deduce the formula of x. N, =6.02 x 10", N =14.0, O = 16.0]

(b)(i) Describe briefly what happens when each of the following substances are added to water:

(I) CCI\(_{4}\); (II) SiCI\(_{4}\),

(ii) Explain briefly why the reactions in (a)(i), (b)(i), (I) and (b)(ii) (II) are different Study the diagram below and answer the questions that follow.

According to the kinetic theory of gases, the pressure exerted by a gas is due to

• A. The vibrations of gas particles.
• B. The weight of the gas particles
• C. The attractive forces between gas particles
• D. The collisions of gas particles with the container walls

What is the product of the electrolysis of aqueous sodium chloride (NaCl) using inert electrodes?

• A. Hydrogen gas at the cathode and chlorine gas at the anode
• B. Hydrogen gas at the cathode and oxygen gas at the anode
• C. Sodium metal at the cathode and chlorine gas at the anode
• D. Sodium metal at the cathode and oxygen gas at the anode

A chemical reaction is always associated with

• A. an increase in the composition of one of the substance
• B. a change in the volume of the reactants
• C. a change in the nature of the reactants
• D. the formation of new substance