Question

question 10 (1 point)
use the following information to answer the next question.
a solution of hydrochloric acid, hcl(aq), is prepared by dissolving 3.7 g of hcl(g) in enough water to make 1.0 l of solution.
the ph of the solution is
0.10
0.99
1.02
1.09
1.72
question 11 (1 point)
what type of solution does the sodium fluoride in mouthwash form in water?
neutral
basic
acidic
acids and basic
question 12 (1 point)

Explanation:

Question 10

Step 1: Calculate moles of HCl

Molar mass of HCl is \(36.46\space g/mol\). Moles \(n = \frac{mass}{molar\space mass}=\frac{3.7\space g}{36.46\space g/mol}\approx0.1015\space mol\).

Step 2: Calculate molarity of HCl

Molarity \(M=\frac{n}{V}\), \(V = 1.0\space L\), so \(M=\frac{0.1015\space mol}{1.0\space L}=0.1015\space M\).

Step 3: Calculate pH

HCl is strong acid, \([H^+]=M = 0.1015\space M\). \(pH=-\log[H^+]=-\log(0.1015)\approx0.99\).

Sodium fluoride (\(NaF\)) dissociates into \(Na^+\) and \(F^-\) in water. \(F^-\) is the conjugate base of weak acid \(HF\), so \(F^-\) hydrolyzes: \(F^-+H_2O
ightleftharpoons HF + OH^-\), producing \(OH^-\), making the solution basic.

Answer:

0.99

Question 11