How would you prepare a 1 L stock solution of 1M Tris FW 12

How would you prepare a 1 L stock solution of 1M Tris? (FW = 121.21)

a. Mix 121g of Tris and fill with water up to 1000mL

b. Mix 121g of Tris and fill with water up to 500mL

c. Mix 60.5g of Tris and fill with water up to 1000mL

d. None of the above

Answer:

a. Mix 121g of Tris and fill with water up to 1000mL

Explanation:

Use the formula mw g / l = 1 M 121.21 g / l = 1 M

Molarity = (W/FW) * (quantity of solution required/1000ml)

1M = (121g/121.21) * (1000ml/1000ml)