Question

Incorrect Question 1 0/4 pts What is the pH of a solution with [H30+1 = 2.19 x 10^M? 3.0 3.7 10.03 6.32 Incorrect Question 2 0/4 pts A solution is prepared by dissolving 111.9 g HCl in enough water to make 160L of solution. The pH of this solution is: O 3.1 O none of these O 17

Answer 1

1)

[H+] = 2.19*10^-4 M

use:

pH = -log [H3O+]

= -log (2.19*10^-4)

= 3.6596

Answer: 3.7

2)

Molar mass of HCl,

MM = 1*MM(H) + 1*MM(Cl)

= 1*1.008 + 1*35.45

= 36.458 g/mol

mass(HCl)= 111.9 g

use:

number of mol of HCl,

n = mass of HCl/molar mass of HCl

=(1.119*10^2 g)/(36.46 g/mol)

= 3.069 mol

volume , V = 1.6*10^2 L

use:

Molarity,

M = number of mol / volume in L

= 3.069/1.6*10^2

= 1.918*10^-2 M

So,

[H+] = 1.918*10^-2 M

use:

pH = -log [H+]

= -log (1.918*10^-2)

= 1.7172

Answer: 1.7