Which of the following reacts with hydrochloric acid to give hydrogen as a product?

Which is the correct statement regarding halogens?

Why is helium added to oxygen which is used by deep-sea divers?

Which among the following noble gases does not form clathrates?

Which of the following is not an oxoacid of chlorine?

What will be the products of the reaction – C2H4 + 2O2 →?

The acidic strength of HClO4 is lesser than HClO.

What is the oxidation state of nitrogen in di-nitrogen trioxide?