Question

How many grams of methionine (MW = 149.21) are needed to make 20 mL of a 150 mM solution?

Answer 1

Answer:

0.45 g

Explanation:

Step 1: Given data

• Molar mass of methionine (M): 149.21 g/mol

• Volume of the solution (V): 20 mL

• Concentration of the solution (C): 150 mM

Step 2: Calculate the moles of methionine (n)

We will use the following expression.

n = C × V

n = 150 × 10⁻³ mol/L × 20 × 10⁻³ L

n = 3.0 × 10⁻³ mol

Step 3: Calculate the mass of methionine (m)

We will use the following expression.

m = n × M

m = 3.0 × 10⁻³ mol × 149.21 g/mol

m = 0.45 g