Question

Exactly 16 mL of a solution A is diluted to 300 mL, resulting in a new solution B that has 0.50 M concentration. If the solution was made with NaCl (58.443 g/mole), determine the number of grams of NaCl needed to make 1.00 L of the original solution A.

Answer 1

Answer:

8.77g

Explanation:

Step 1:

Data obtained from the question.

This includes the following:

Concentration of A (C1) =.?

Volume of A (V1) = 16 mL

Volume of B (V2) = 300 mL

Concentration of B (C2) = 0.50 M

Molar Mass of NaCl = 58.443 g/mol

Mass of NaCl =.?

Step 2:

Determination of the concentration of A.

Applying the dilution formula:

C1V1 = C2V2

The concentration of A i.e C1 can be obtained as follow:

C1V1 = C2V2

C1 x 16 = 0.5 x 300

Divide both side by 16

C1 = (0.5 x 300) / 16

C1 = 9.375 M

Therefore, the concentration of A is 9.375 M

Step 3:

Determination of the number of mole of NaCl in 9.375 M NaCl solution. This is illustrated below:

Molarity = 9.375 M

Volume = 16 mL = 16/1000 = 0.016 L

Mole of NaCl =?

Molarity = mole /Volume

Mole =Molarity x Volume

Mole of NaCl = 9.375 x 0.016

Mole of NaCl = 0.15 mole

Step 4:

Determination of the mass of NaCl. This is illustrated below:

Mole of NaCl = 0.15 mole

Molar Mass of NaCl = 58.443 g/mol

Mass of NaCl =?

Mass = number of mole x molar Mass

Mass of NaCl = 0.15 x 58.443

Mass of NaCl = 8.77g

Therefore, 8.77g of NaCl is needed to make 1 L of the original solution A.

Answer 2

Answer:

We need 8.77 grams of NaCl

Explanation:

Step 1: Data given

Volume of solution A = 16 mL = 0.016 L

Volume of solution B = 300 mL = 0.300 L

Concentration of solution B = 0.50 M

Step 2: Calculate molarity of solution A

C1*V1 = C2*V2

⇒with C1 = the concentration of solution A = TO BE DETERMINED

⇒with V1 = the volume of solution A = 0.016 L

⇒with C2 = the concentration of solution B = 0.50 M

⇒with V2 = the volume of solution B = 0.300 L

C1 * 0.016 L = 0.50 M * 0.300 L

C1 = 9.375 M

Step 3: Calculate moles of solution A

Moles = molarity * volume

Moles = 9.375 M * 0.016 L

Moles = 0.15 moles

Step 4: Calculate mass of NaCl needed

Mass NaCl = moles / molar mass

Mass NaCl = 0.15 moles * 58.443 g/mol

Mass NaCl = 8.77 grams

We need 8.77 grams of NaCl