Which of the following is an example of strong base?

The salt solution which does not react with ammonium hydroxide is:

If $\mathrm{pH}$ of a solution is 13, means that it is

In order to determine the acidic, basic or neutral character of solutions, a student tabulated the following results after experimentation. Which of the following observations has been tabulated correctly? 

Consider the following salts and their common names:

1. Copper sulfate - blue vitriol

2. Iron sulfate - green vitriol

3. Sodium carbonate - baking soda

Which of the above matches is/are correct?

A student burns a magnesium ribbon in the air and dissolves the ash of the ribbon left after burning in the distilled water. On pouring one drop each of this solution, first in blue litmus and then in red litmus solution, he would observe that _____.

Select the wrong statement

I. Compounds are made up of two or more elements in definite proportion.

II. Mixtures contain elements in any proportion.

III. Milk is a homogeneous mixture.

IV. Air is a homogeneous mixture.

Which of the given statement(s) is or are incorrect?

The following observations were made by students A, B, C, and D when they rubbed solid baking soda on dry litmus paper.

The correct observation was made by _____.

The $\mathrm{pH}$ of a compound is found to be 9. The compound can be