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

Water is a good solvent. This is due to high

The bond which is present between water molecules is

Which one among the following is the chemical formula of gypsum which is an ingredient of cement?

The pure form of carbon is