Question

what is the total formula mass in amu for lactose, c₁₂h₂₂o₁₁?

154.25 amu
90.08 amu
342.3 amu
340.28 amu

Explanation:

Step1: Add the total mass of each element

$$144.12 + 22.22+176.00$$

Step2: Calculate the sum

$$144.12+22.22 = 166.34$$
$$166.34 + 176.00=342.34\approx342.3$$

Answer:

342.3 amu