The acid in gastric juice is

Which one among the following is not a chemical change?

The acid contained in vinegar is

A positively charged particle projected towards west is deflected towards north by a magnetic field. The direction of the magnetic field is

Metal used to make wires for safety fuses must have

Which of the following statements regarding the property of hard water is/are correct?

1. Temporary hardness of water is due to the presence of soluble magnesium and calcium hydrogen carbonate
2. Temporary hardness of water can be removed by boiling
3. Calgon’s method is applied to remove temporary hardness of water
4. Permanent hardness of water is removed by Clark’s method

Select the correct answer using the code given below