CLASS TASK 1

Which of the following raw materials is used in the plastics industry?

• Ethene

• Methane

• Sulphur

• Hydrogen

An acidic salt has

• double anions in its aqueous solution

• a single cation in its aqueous solution

• hydrogen ions in its aqueous solution

• hydrogen atoms in its aqueous solution

What is the solubility of a salt if 0.4g of it is obtained on evaporating 200cm³ of its saturated solution to dryness?

• 0.08gdm^-3

• 2.00gdm^-3

• 8.00gdm^-3

• 80.00gdm^-3

A reaction is endothermic if the

• reaction vessel feels cool during the reaction

• enthalpy change is negative

• bond forming energy exceeds bond breaking energy

• heat of formation of reactants exceeds heat of formation of products

In which of the following compounds does hydrogen form ionic compounds?

• CH₄

• HCl

• NH₃

• NaH

Consider the following reaction equation: Br2 + 2KI

 $\rightarrow$  2KBr + I2  Bromine is acting as

• an oxidizing agent

• a reducing agent

• an acid

• a base

An oragnic compund has the empirical formula CH₂. If its molar mass is 42gmol^-1. What is its molecular formula? [H = 1, C = 12]

• C₂H₄

• C₃H₄

• C₃H₆

• C₄H₈

Ethene is produced from ethanol by decomposition

• decomposition

• hydrolysis

• ozonolysis

• dehydration

Consider the following equilibrium reaction: 2AB2(g) + B2(g)  $\leftrightarrow$    2AB3(g)  $\Delta$   = -Xkj/mol The backward reaction will be favoured by

• a decrease in pressure

• an increase in pressure

• a decrease in temperature

• an introduction of a positive catalyst

What is the mass of solute in 500cm³ of 0.005mol/dm³ H₂SO₄? [H= 1, O = 16, S = 32]

• 0.490g

• 0.049g

• 0.245g

• 0.0245g