Question

1 litre of 2.1 m hcl solution is taken and 965 amp of current is passed for 200 seconds . then find the pH of the solution

Answer 1

Answer:

Equation representing the electrolysis of aqueous NaCl:

2NaCl(aq) +2H_{2}O(l) --->2 Na^{+}(aq)+2OH^{-}(aq)+H_{2}(g)+ Cl_{2}(g)  

Current I = 5.0 A

Time t = 965 s

Charge Q = It

= 5.0 A (965 s)

= 4,825 C

Moles of NaCl = 0.5 L × \frac{1.0 mol}{L}   = 0.5 mol NaCl

4825 C ×  \frac{1 mol  e^{-}}{96485C}   × \frac{2 molNaOH}{2 mol e^{-}}    = 0.05 mol NaOH

\frac{0.05 mol}{0.5 L} = 0.1M  

pOH =-log[OH^{-}] \\             = 1  

pH + pOH = 14.00

pH = 14.00 - 1 = 13

Explanation: