Question

Find the pH of the following: Show all work

1. 0.020 moles  of  HCl  in 20.0 L of water
2. 6 grams NaOH ( MW 40 g/mol)  in 15 L of water
3. The titration  where Va= 5 mL   Vb= 20 L Ma= 0.40  Mb= ?

Answer 1

$M= \frac{0.020}{20}=1.0×10^{-3}$

pH = -log (M)

pH= $-log(1.0×10^{-3})= 3$

Question 2

$Moles = \frac{6}{40}=0.15 moles$

$M= \frac{0.15}{15}=0.01$

$pH=-log(0.01)=2$