Which one of the following statements is not true?

  • Option 1)

    The conjugate base of H_{2}PO{_{4}}^{-} is HPO{_{4}}^{2-}
     

  • Option 2)

    pH+pOH= 14\: for \: all \: aqueous\: solutions.

  • Option 3)

    The\: pH\: of\: 1\times 10^{-8}M\: H\! C\! L \: is \: 8

     

  • Option 4)

    96,500 coulombs of electricity when passed through a CuSO_{4} solution deposits 1 gram equivalent of copper at the cathode.

 

Answers (1)

As we learnt in 

Value of p(H) -

Acidic solution has p(H)  < 7

Basic solution has  p(H)  > 7

Neutral solution has p(H) = 7

:pH of an acid cannot exceed 7 Here we should also conside \left [ H^{+} \right ] that comes from H_{2}O

Now\left [ H^{+} \right ]= \left [ H^{+} \right ]_{from HCl}+\left [ H^{+} \right ]_{from\: H_{2}O}

= 10^{-8}+10^{-7}= 10^{-8}+10\times 10^{-8}= 11\times 10^{-8}

\therefore pH= -\log \left ( 11\times 10^{-8} \right )= 6.9587

 


Option 1)

The conjugate base of H_{2}PO{_{4}}^{-} is HPO{_{4}}^{2-}
 

This option is incorrect.

Option 2)

pH+pOH= 14\: for \: all \: aqueous\: solutions.

This option is incorrect.

Option 3)

The\: pH\: of\: 1\times 10^{-8}M\: H\! C\! L \: is \: 8

 

This option is correct.

Option 4)

96,500 coulombs of electricity when passed through a CuSO_{4} solution deposits 1 gram equivalent of copper at the cathode.

This option is incorrect.

Most Viewed Questions

Preparation Products

Knockout JEE Main April 2021 (One Month)

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 14000/- ₹ 4999/-
Buy Now
Knockout JEE Main May 2021

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 22999/- ₹ 9999/-
Buy Now
Test Series JEE Main May 2021

Unlimited Chapter Wise Tests, Unlimited Subject Wise Tests, Unlimited Full Mock Tests, Get Personalized Performance Analysis Report,.

₹ 6999/- ₹ 2999/-
Buy Now
Knockout JEE Main May 2022

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Live Classes, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 34999/- ₹ 24999/-
Buy Now
JEE Main Rank Booster 2021

Booster and Kadha Video Lectures, Unlimited Full Mock Test, Adaptive Time Table, 24x7 Doubt Chat Support,.

₹ 13999/- ₹ 6999/-
Buy Now
Boost your Preparation for JEE Main 2021 with Personlized Coaching
 
Exams
Articles
Questions