Which of the following elements of the halogen family is in a liquid state at room temperature?

Which one of the following orders is not in accordance with the property stated against it?

Sodium chloride when heated with conc. $H_2SO_4$ and solid potassium dichromate gives

When chlorine gas is passed through an aqueous solution of a potassium halide in the presence of chloroform,a violet colouration is obtained. On passing more of chlorine water,the violet colour disappears and the solution becomes colourless. This test confirms the presence of ........... in the aqueous solution.

Which of the following reactions does not take place?

The element which can displace three other halogens from their compound is