Question

45g acid of mol. wt. 90 neutralised by 200 ml of 5n caustic potas .the basicity of the acid us

Answer 1

45g of acid of mol wt 90.
It means 1 mole of acid weighs 90g
thus 45g of the acid will weigh 0.5moles

Thus 0.5moles is neutralised by 200mL of 5N caustic potash, i.e. 0.5*2 = 1 gm.equivalent.

Thus 1 gm equivalent of caustic potash is equal to 56g. 56g of caustic potash has 1 mole.

Thus overall
0.5 mole of acid is neutralised by 1 mole of caustic potash. Thus to neutralise 1 mole.of acid we need to moles of base,

thus acid is dibasic

Answer 2

Answer:

The basicity of acid is 2....

Explanation:

Weight of acid =0.45g

Moles = 900.45 = 21 ×10 −2 =5 millimoles

N 1 V 1 =N 2 V 2

(5×10 −3 )×basicity=20×0.54×10 −3

basicity≈2

Hence, option B is correct