Question

4.The pH of NaOH solution is 10.6. On addition of water to this solution its pH *
1 point
(a) remains same
(b) increases
(c) decreases
(d) becomes 7​

Answer 1

Answer:

(c) decreases

NaOh is base

On addition of water it's pH will move towards neutral value (7)

Therefore its pH value decreases

Answer 2

.The pH of NaOH solution is 10.6. On addition of water to this solution its pH (b) Increases

• Peter Sorensen a danish biochemist suggested/invented this method of expressing concentration of H+ ions in terms of pH.
• hence, pH stands for protenz de hydrogen in Danish language and which means power of H+ ions.
• pH = log 1/ [H+] where H+ is concentration of hydrogen ions.

Here,

• NaOH sodium hydroxide in a crystalline form contains Na+ anions and OH- cations.
• On adding. water with more OH- cations to the NaOH solution, the molecule of sodium hydroxide NaOH gets dissociated in the ion form as Na+ and OH-.
• And they concentration of hydroxyl ions OH- cations increases.
• NaOH => OH- + Na+
• As a result , increased number of OH- ions(hydroxyl ions) lead to increase in basic nature of the solution which eventually gives a significant increase of the pH of solution.