Question

solid sodium bicarbonate was placed on a strip of pH paper. the colour of the strip

turned blue

did not change

turned green

turned light pink

Answer 1

Did not change. Since sodium carbonate is in solid form. Ions dissociate in aqueous solutions only.

Answer 2

answer : did not change

explanation : A salt is formed by two components . one component is a part of acid and other component is part of base. if base part is strong , then salt will be basic in nature and if acid part is strong, then salt will be acidic in nature.

here given, sodium carbonate (NaHCO3)

Na^+ is came from sodium hydroxide (NaOH), a strong base.

and (HCO3)- is came from carbonic acid (H2CO3), a weak acid.

it is clear that, NaHCO3 is formed by strong base and weak acid. so, NaHCO3 is basic in nature or it is a basic salt.

now, it means when we place strip of pH paper in aqueous sodium bicarbonate, the colour of strip turns into blue.

but here given, solid sodium bicarbonate, and we know, pH paper can't change its colour in solid compound( because in solid state compound doesn't dissociate into ions.)

hence, strip colour did not change.