Question

4. Each time that you prepare a diluted bleach solution you will want it to have a [OH-] = 0.02. Calculate how much 1.00 M NaOH you need to add to d.1. water to get every 20 mL of this concentration of OH- ion. Express your answer in drops of 1.00 M NaOH. (Assume that there are 20 drops in 1 m.)

Answer 1

Answer:

8 drops of 1.00 M NaOH will be needed.

Explanation:

Concentration of $[OH^-]$ in bleach solution = 0.02 M

$NaOH\rightarrow OH^-+Na^+$

$NaOH=[OH^-]=0.02M$

Concentration of bleach solution we want ,$M_1$ = 0.02 M

Volume of the bleach solution,$V_1$ = 20 ml

Concentration of NaOH solution,$M_2$ = 1.00 M

Volume of the NaOH solution required ,$V_2$ = ?

$M_1V_1=M_2V_2$

$0.02 M\times 20 mL=1.00 M\times V_2$

$V_2=\frac{0.02 M\times 20 mL}{1.00 M}=0.4 mL$

1 mL = 20 drops

0.4 mL = 0.4 × 20 drops = 8 drops

8 drops of 1.00 M NaOH will be needed.