Question

What will be the mass of carbon dioxide made from ${}_6^{14}\text{C}$?

• A. 44 u
• B. 46 u
• C. 48 u
• D. 50 u

Answer 1

The correct option is B 46 u

The molecular formula of carbon dioxide is $C{O}_2$.
Atomic mass of ${}_6^{14}\text{C}=14u$
Atomic mass of ${}_8^{16}\text{O}=16u$
Molecular mass of $C{O}_2$ made from ${}_6^{14}\text{C}=$ Atomic mass of ${}_6^{14}\text{C}$ + 2 x Atomic mass of ${}_8^{16}\text{O}$)
= 14 u + 2 x 16 u = 46 u.