INSTRUCTION:- show your working and post your answer into the COMMENT OR JOIN DISCUSSION BOX below the question.

QUESTION

A tribasic acid recorded 3 on the screen of a pH meter when analyzed, calculate the molarity of the acid.

(A). 0.02

(B). 0.04

(C). 0.09

(D). None

Goodluck…

Chidocks

Answer: (D) None

Reason:

Tribasic Acid implies → 3H^+

pH = 3

Formula: pH = -log(H+) Note Log is to base 10

Substitute (H^+) for (3H^+) as we are dealing with a tribasic acid

3 = -log (3H^+)

Just switch

-log (3H^+) = 3

log (3H^+) = -3

(3H^+) = {10^-3} ÷ {3}

(H^+) = 0.00033

Therefore, Molarity = 0.0003 {4d.p}

Nice work

A tribasic acid has three hydrogen atoms hence

[3H^+]

pH is given As 3

pH = -log[3H^+]

3 = -log[3H^+]

Log[3H^+] = -3

[3H^+]= 10^-3

H^+ =0.001/3

H^+ = 0.003mol per dm^3

Hence the answer is D(none)

0.0003 mol per dm^3 as main answer

The answer is D

PH = -log [H^+]

3 = – log 3[H^+]

3[H^+] = 1/10^3

[H^+] = 1/3000

[H^+] = 3.3×10^4 = 0.00033mol/L

Let the molarity be x

From the formula we understand that

pH= -log(H+)

Sub…

We’ve….

3= -log(3x)

In3 = 3x

1.0986 = 3x

x =0.366M

pH = 3

Tribasic acid = 3H^+

Formula for pH = – Log(H^+)

=> – log(3H^+) = 3

=> log(3H^+) =-3

3H^+ = 10^-3

3H^+ = 0.001

H^+ = 0.0003M

D. (None)

pH= -log(H+)

pH = 3

10^3=1\H+

Therefore H+ = 1\1000= 0.001

Ans= D

Answer is D.

Using calculator method,

pH = -log[H+]

-log[H+] = pH

-log[H+] = 3

H+ = (antilog, 10^-3, I.e, the 2nd function on the log key on the calculator,(i.e that of 10^x which is antilog of the number. Press shift button and then log button followed by the negative sign button (-), followed by the number, in this case, 3, which will appear as -3 in advanced scientific calculator).

[H+] = 10^-3

= 1×10^3.