Question

Now dilute 10.0 mL of the 0.50 M NaCl by adding distilled water until 100 mL of solution are produced.

Do the 100 mL of diluted NaCl have more, less, or the same quantity of NaCl as the original 10.0 mL of 0.50 M NaCl?

more
less
the same

Answer 1

My teacher just explained this problem to me and she said it is "the same".

Answer 2

Answer: the same

Explanation:

According to the dilution law,

`M_1V_1=M_2V_2`

where,

`M_1` = molarity of stock solution = 0.50 M

`V_1` = volume of stock solution = 10 ml= 0.01 L (1L=1000ml)

`M_2` = molarity of resulting solution = ? M

`V_2` = volume of resulting solution = 100 ml = 0.1 L

`(0.50M)* 0.01=(M_2)* (0.1ml)`

`M_2=0.05M`

Therefore, the Molarity of resulting solution is 0.05 M

`Molarity=\frac{moles}{\text {Volume in L}}`

1. when volume is 10 ml or 0.01L (1L=1000ml)

moles of
`NaCl=Molarity* {\text {Volume in L}}=0.50* 0.01=5* 10^(-3)moles`

2. when volume is 100 ml or 0.1L (1L=1000ml)

moles of
`NaCl=Molarity* {\text {Volume in L}}=0.05* 0.1=5* 10^(-3)moles`

Thus they contain same amount of
`NaCl`.