acids, bases, salts and metals - Category wise Question and Answer Practice Test with Solutions

Question : 16 [NDA]

Neutral water with pH about 7 becomes slightly acidic when aerated. This is because

a) ultraviolet radiation dissociates water molecules and makes water acidic

b) oxygen from air is dissolved in the water which makes the water acidic

c) dirt, which get contaminated with the water during aeration makes the water acidic

d) carbon-dioxide from air is dissolved

Question : 17

Universal indicator solution is named as such because

a) it has a universal appearance

b) it can be used for entire pH range

c) it is available universally

d) all the above are correct

Question : 18

Match Column-I with Column-II:

a) A – R; B – S; C – Q; D – P

b) A – S; B – R; C – Q; D – P

c) A – P; B – R; C – Q; D – S

d) A – S; B – Q; C – R; D – P

Question : 19

The reaction of metal with acid results in the formation of–

a) only salt

b) both salt and hydrogen gas

c) only hydrogen gas

d) none of these

Question : 20

Which of the following pairs of substances are chemically same?

a) Dead burnt plaster and gypsum

b) Both the above

c) Lime water and milk of lime

d) None of the above