Question

A student must prepare 7.00 L of 0.100 M Na2CO3 (106 g/mol). Which is the best procedure for preparing this solution

Answer 1

Answer:

Measure 74.2 g Na2CO3 and add H20 until the final homogeneous solution has a volume of 7.00 L

Explanation:

The best procedure is

Mole of

$Na_2CO_3 = Volume \times molarity\\\\= 7.00 L \times 0.100 mol$

= 0.700 mol

The mass of

$Na_2Co_3 = Moles \times molar\ mass \\\\= 0.700 mol \times 106 g/mol$

= 74.2 g

So as per the above calculation, the option 3 is correct as the solution volume is 7.00 L so the same is to be considered

hence, all other options are wrong