Pure Substances

What is compound?

Copper sulphate crystals available in the market are blue coloured crystals. By careful heating, they turn to white colour. Which one of the following is responsible for the blue colour?

Which among the following is the popular method for the manufacture of ammonia?

Which one of the following is the correct arrangement of metals in the decreasing order of their reactivity?

Define the following term:

Compound 

What is a compound?

What is $\mathrm{NaCl}$?

Choose the incorrect statement from the following:

Is ${\mathrm{O}}_2$ an element or compound?

Water containing $88.8 \%$ oxygen and $11.2 \%$ hydrogen is often used as a fire extinguisher. Can a mixture containing the two gases in the same ratio by mass be used for extinguishing fire?

Which is a liquid metal?

Give reason.

Pure substance is made up of similar particle but water is not made up of similar particle and is pure.

What is an element?

A scientist found that two samples of the same compound had the same elements combined in different ratios. Was the finding correct? 

What is the difference between a mixture and a compound on the basis of their constituents? 

Why is blood called a mixture and zinc an element?

If the statement is false, rewrite it correctly.

Hydrogen and oxygen are combined in $1:8$ ratio by mass.

If the statement is false, rewrite it correctly.

The constituents of a compound cannot be separated by physical means.

What are the substances combined chemically called?

Antimony is a metal.