C and D are samples of two different simple salts. Carry out the following exercises on them. Record your observations and identify any gases evolved. State the conclusion you draw from the result of each test.

a) Heat about one-half of C in a dry test tube until no further change is observed. Allow to cool.

(b)(i) To the cooled residue from (a) above, add about 5cm\(^3\) of dilute hydrochloric acid and warm.

(ii) To about 2cm\(^3\) of the clear solution from (b)(i) above add aqueous ammonia in drops until it is in excess.

(c)  Put all of D in a boiling tube and add about 10cm\(^3\) of distilled water. Shake thoroughly and divide into two portions.

(d)(i) To the first portion from (c) above, add about 2cm\(^3\) of barium chloride solution, followed by dilute hydrochloric acid in excess. Warm the mixture.

(ii) To the second portion from (c) above, add 2 or 3 of acidified potassium tetraoxomanganate (VII) solution and shake.