Question

An empty weighing dish has a mass of 1.0041 ± 0.0002 g. After you add dried sodium chloride to the dish, the mass is 3.2933 ± 0.0002 g. You quantitatively transfer the sodium chloride into a 500.00 ± 0.05 mL volumetric flask and dilute to the mark with deionized water. The molar mass of sodium chloride is 58.440 g/mol. What is the absolute error in the concentration of the resulting solution? Report your answer normally to the correct number of significant figures with the correct unit.

Answer 1

The correct answer to the following question will be "0.0013%".

Step-by-step explanation:

The given values are:

Weight of an empty dish = 1.0041 ± 0.0002 g

Weight of dish + sodium chloride (NaCl) = 3.2933 ± 0.0002 g

Weight of NaCl = 2.2892 ± 0.0002 g

Now,

Volume of the solution = 500.00 ± 0.05 ± 0.0002

= 500.00 ± 0.0502 ml

So,

Molarity =
`(W \ NaCl)/(M \ NaCl) * (1000)/(Volumes \ of \ solution)`

On putting the values in the above formula, we get

=
`((2.2892\addeq +0.0002))/(58.440)* (1050)/((500.00+0.0502))`

= (
`3.917` ±
`0.0002`) × (
`2` ±
`0.0502`)

= (
`0.7834` ±
`.00001004`)

Now,

Absolute error =
`(0.00001004)/(0.7834)* 100`

=
`0.0013`%