Question

please answer questions 2 and 3

QUESTION 2 What mass of NaCl is needed to prepare 100.0 mL of 0.500 M NaCl solution? O 0.856 g O 0.342 g O 2.92 g O 1.17 g QUESTION 3 What volume of 5.00 M NaOH stock solution is needed to prepare 100.0 mL of 0.250 M NaOH solution? O 0.200 mL 0 12.5 mL 5.00 mL 80.0 mL Click Save and submit to save and submit. Click Save an Anen

Answer 1

Question 2.

Ans: 2.92 g

Molecular weight of NaCl is 58.44. So 58.44 g in 1000 mL is 1M.

29.2 g in 1000 mL is 0.5 M solution, we need 100 mL, so 2.92 g in 100 mL is 0.5 M.

Question 3.

Ans: 5mL

Formula to calculate volume is,

M1×V1= M2×V2

5× V1= 100× 0.25

V1= 25/5

V1= 5 mL