Question

1. True or False Since this laboratory uses household products, it is not necessary to a. wear safety goggles while performing the experiment. b. It is not necessary to keep track of significant figures for titration laboratories. c. A strong acid is an acid that completely dissociates in water. 2. Given a 0.25M solution of hydrochloric acid, determine the hydronium ion concentration and the pH. 3. A student titrates a 25.0mL aliquot of HCI with a buret of 1.002M NaOH. The initial buret reading was 0.02mL and the final buret reading was 27.80mL. What is the concentration of the HCl solution?

Answer 1

PART 1:

1. Since this laboratory uses household products, it is not necessary to wear safety goggles while performing the experiment. -FALSE (Strong acids, bases, glasswares etc. are dangerous and may cause sever injuries. Hence, wearing safety goggles while performing the experiment are necessary)
2. It is not necessary to keep track of significant figures for titration laboratories-FALSE (It is necassy to keep track of significant figures otherwise, the final result may end up in a uncertain value)
3. A strong acid is an acid that completely dissociates in water-TRUE (strong acids will completely dissociates in water whereas weak acids dissociates partially in water)

PART 2:

HCl is a strong acid, hence HCl completely dissociates into H⁺ ion and Cl^- ions.

Hence, Concentration of H⁺ ions is given by,

$[H^{+}]=[HCl]=0.25\;M$

Therefore, Hydronium ion concentration:

$[H_{3}O^{+}]=[H^{+}]=0.25\;M$

We know that, pH is given by,

$pH=-\log [H^{+}]=-\log\left ( 0.25\;M \right )$

$\therefore pH=-\left ( -0.602\right )$

$\boldsymbol{\therefore pH=0.602}$

NOTE: Please post one question at a time, we are allowed to answer one part at a time.