Question

what is the formula mass of sulfurous acid?

a. 82.08 amu

b. 98.08 amu

c. 83.09 amu

d. 66.08 amu

e. 77.00 amu

Explanation:

Step1: Determine the formula of sulfurous acid

Sulfurous acid has the chemical formula \( \ce{H_2SO_3} \).

Step2: Find the atomic masses of each element

• Atomic mass of \( \ce{H} \): \( 1.008 \) amu (there are 2 H atoms)
• Atomic mass of \( \ce{S} \): \( 32.07 \) amu (there is 1 S atom)
• Atomic mass of \( \ce{O} \): \( 16.00 \) amu (there are 3 O atoms)

Step3: Calculate the formula mass

Formula mass \( = (2 \times \text{atomic mass of } \ce{H}) + (\text{atomic mass of } \ce{S}) + (3 \times \text{atomic mass of } \ce{O}) \)
\[

$$\begin{align*} &= (2 \times 1.008) + 32.07 + (3 \times 16.00) \\ &= 2.016 + 32.07 + 48.00 \\ &= 82.086 \approx 82.08 \text{ amu} \end{align*}$$

\]

Answer:

a. 82.08 amu