Chemistry in Everyday Life — CHEMISTRY STD 7 — Question

Statement are incorrect. write the correct statement:
While writing a chemical equation, one need not to know whether the reaction takes place between two or more reactants.

The king of chemicals

Name the following.
A catalyst used in the laboratory preparation of oxygen from hydrogen peroxide.

Write the chemical formulae : Limestone

Statement are incorrect. write the correct statement:
During a physical change new products are formed.

Statement are incorrect. write the correct statement:
The components of a mixture are present in a fixed ratio.

What do you observe in the following cases.
A drop of phenolphthalein is added to sodium hydroxide solution

Statement are incorrect. write the correct statement:
The symbol NaHCO3 stands for washing soda.

Statement are incorrect. write the correct statement:
Kerosene oil is separated from the mixture of kerosene oil and water by the process of distillation.