Question

Titration Curves of Pre-lab questions. rves of Strong and Weak Acids and Bases. e 1. Explain the difference between a stre xplain the difference between a strong acid and a weak acid. **Calculate the pH of an HC Solution in which the H.01 -1.75 x 10°M. Calculate the pH of a NAOH solution in which the (OH) 3.7 x 10" M. Labc 4. Calculate the [H.O') when pH = 7.42 5. Calculate the [H3O+] when pOH = 5.43 6. Calculate the pH of 1.00 Macetic acid, HC,H,O2 (aq). (Ka = 1.8 x 10%) 7. Calculate the Ka of a 0.50 M HC.H-O, with a pH of 2.56.

Answer 1

1. Strong acid which dissociates completely where as in weak acid there exists an equilibrium between dissociated form and undissociated form.

Strong acids ionize completely where as weak acids do not ionize completely.

2.

Given that [H₃O^​+] = 1.75×10^-3 M

pH = -log[H₃O⁺] = -log 09(1.75×10^-3)

= -log(1.75) - log(10^-3) ( Since log AB = log A + log B )

pH = 3-log1.75 = = 3 - 0.243 = 2.76

3.

Since [OH^{​​​​​-}​] is given, first we need to calculate the pOH and from pOH we can calculate the pH.

pOH = -log[OH^{​​​​​-}] = -log(3.7×10^-4)

= -log(3.7) - log(10^-4) ( Since log AB = log A + log B )

pOH = 4-log3.7 = = 4 - 0.568 = 3.432

Since pH + pOH = 14

pH = 14 -pOH = 14 -3.432 = 10.568

4)

pH = -log( H⁺)

[H⁺ ] = 10^{-pH =} 10^-7.42

= 3.8×10^-8