Answer:
The correct answer is - A. ammonia blue.
Explanation:
It is given that there is a mixture of ammonium chloride and sodium hydroxide and if we heat the Mixture of NH4Cl and NaOH then, the following reaction will take place-
NH4Cl (aq)+ NaOH (aq)==> NaCl (aq) + NH3 (g)+ H2O (l)
In this reaction, there is a release of NH3 gas which is absorbed on litmus paper. We know that NH3 gas is basic in nature and so it will turn litmus paper blue.
Thus, the correct answer would be - NH3 (ammonia ) and Blue