A mixture is made by adding 50.0 mL of 0.20 M NaOH(aq) to 50.0 mL of water. At 25.0 °C, what is its pH?

13

Explanation:

From the dilution formula;

C1V1 = C2V2

C1= concentration of the stock solution = 0.2 M

V1 = volume of the stock solution = 50.0 ml

C2= concentration of the diluted solution= the unknown

V2= volume of diluted solution= 100 ml

C2= C1V1/V2

C2= 0.2 × 50/100

C2= 0.1 M

But

pOH= -log[OH^-]

But [OH^-] = 0.1 M

pOH= -log [0.1]

pOH= 1

Since;

pH +pOH = 14

pH= 14 - pOH

pH= 14- 1

pH= 13

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current