How many isomers does pentane have?

• A. 6
• B. 5
• C. 4
• D. 3

The leachate of a certain plant ash is used in local soap making because it contains

• A. sodium chloride and potassium hydroxide
• B. sodium hydroxide
• C. potassium hydroxide
• D. soluble carbonates and hydrogen carbonates

When cathode rays are deflected onto the electrode of an electrometer, the instrument becomes

• A. negatively charged
• B. positvely charged
• C. neutral
• D. bipolar

The murmurings of the congregation in the wilderness against Moses and Aaron were an indication of the people's

• A. lack of patience with them
• B. lack of fath in them
• C. fear of dying by the sword
• D. inability to get to the promise land

Which of the following is physical change?

• A. Burning kerosene
• B. Freezing ice cream
• C. Exposing white phosphorus
• D. Dissolving calcium in water

Hydrogen can be displaced from a hot alkaline solution by

• A. Fe
• B. Cu
• C. Ca
• D. Sn

When 10g of sodium hydroxide is dissolved in 1000cm³ of water, the sodium formed is approximately [Na = 23, H = 1, O = 16]

• A. 0.01 mol dm^-3
• B. 0.10 mol dm^-3
• C. 0.25 mol dm^-3
• D. 0.50 mol dm^-3

In the electrolysis of a concentrated solution of sodium chloride using electrodes, which of the following ions are discharged at the cathode and anode respectively?

• A. Na⁺ and Cl^-
• B. Na⁺ and OH^-
• C. H⁺ and OH^-
• D. H⁺ and Cl^-

Chlorine gas turns a damp starch-iodide paper

• A. pink
• B. colourless
• C. red
• D. dark blue

The weakest attractive force that can be observed between two molecules is

• A. ionic
• B. covalent
• C. coordinate covalent
• D. van der Waals