Question

q4. what is the formula mass (fm) for cobalt(iii) chlorate, co(clo3)3?
a) 110.38 amu
b) 309.28 amu
c) 331.16 amu
d) 250.35 amu

Explanation:

Step1: Identify atomic masses

The atomic mass of Co (cobalt) is approximately 58.93 amu, Cl (chlorine) is approximately 35.45 amu, and O (oxygen) is approximately 16.00 amu.

Step2: Calculate mass from formula

In $Co(ClO_3)_3$, there is 1 Co atom, 3 Cl atoms, and 9 O atoms.
The contribution of Co: $1\times58.93$ amu = 58.93 amu.
The contribution of Cl: $3\times35.45$ amu = 106.35 amu.
The contribution of O: $9\times16.00$ amu = 144.00 amu.

Step3: Sum up the masses

$FM=58.93 + 106.35+144.00$ amu = 309.28 amu.

Answer:

B. 309.28 amu