EChemTest - Demotest

DEMO TEST n.1

Question 1 / 9

The following schematic diagram represents the fractional distillation of crude oil (crude petroleum) in industry. The letters A to E denote different products obtained from the distillation.

Question: Which one of the fractions A to E has the lowest boiling point range?

Answer:

Question 2 / 9

Which one of the substances listed below is not an element ?

Copper

Water

Oxygen

Hydrogen

Iron

Question 3 / 9

What is the change in oxidation number (oxidation state, valency) of manganese in the reaction represented by the following equation: MnO₂ + 4HCl → MnCl₂ + Cl₂ + 2H₂O

Question 4 / 9

Which of the following substances are liquid at room temperature and standard pressure?

Ethanol

Mercury

Carbon monoxide

Aluminium

Water

Question 5 / 9

Which of the following does not lead to an increase in the nitrogen content of soil?

Growing wheat in the soil

Applying nitrogenous fertilisers

The action of Clostridium and Azobacteria bacteria

Growing leguminous plants in the soil

Rainfall and snowfall

Question 6 / 9

The process whereby hydrocarbons of high molecular mass are converted into hydrocarbons of low molecular mass is called:

Fractional distillation

Cracking

Decomposition

Condensation

Disintegration

Question 7 / 9

The ability to conduct electricity readily is a property of ...

metals

non-metals

halogens

semiconductors

glass

Question 8 / 9

How is the presence of ions in an aqueous solution most directly detected?

By measuring the density of the solution and comparing it with the density of pure water.

By evaporating the solution and testing the residue for conductivity.

By finding out if it conducts electricity.

By adding an ionic substance to the solution and seeing whether there is a reaction.

By measuring whether the solution has an electric charge.

Question 9 / 9

The main component of paper is ...

Cellulose

Clay

Cellophane

Hemicellulose

Celluloid

Submit