Question

fe(no₃)₃
express your answer in atomic mass units to two decimal places.
formula mass =
amu

Explanation:

Step1: Identify atomic masses

Atomic mass of Fe: $55.85$ amu, N: $14.01$ amu, O: $16.00$ amu.

Step2: Count atoms in $\ce{Fe(NO3)3}$

Fe: 1, N: 3, O: $3\times3 = 9$.

Step3: Calculate formula mass

Formula mass = $(1\times55.85)+(3\times14.01)+(9\times16.00)$
= $55.85 + 42.03 + 144.00$
= $241.88$ amu.

Answer:

241.88