Question

What is the mass of 1.5 moles of $C{{O}_{2}}$?

Answer 1

Hint: One mole of any atom always contains the same amount of particles which is equal to the Avogadro number. The molar mass of any molecule is the mass in Avogadro number of atoms, which are considered as 1 mole. The relation between number of moles and mass is the number of moles is equal to given mass upon molar mass.

Formula used: $n=\dfrac{m}{M}$ where, n is number of moles, m is mass, M is molecular mass.

Complete answer:
We have to find the mass of 1.5 moles of $C{{O}_{2}}$. We can calculate the mass of carbon dioxide by the formula for taking out the number of moles, which is $n=\dfrac{m}{M}$ where, n is the number of moles, m is the mass, M is the molecular mass of carbon dioxide. So, we have n = 1.5 moles, molecular mass of carbon dioxide is, molar mass of C + 2 (molar mass of O) , which is,
Molecular mass of $C{{O}_{2}}$= 12 + 32
Molecular mass of $C{{O}_{2}}$= 44 g/ mol
Therefore, rearranging the number of moles formula for mass, we have, m = n$\times $M
m = 1.5 moles $\times $ 44 g/ mol
m = 66 g.
Hence the mass of 1.5 moles of $C{{O}_{2}}$ is 66 g.

Note:
This problem can also be solved through unitary method calculations, as 1 mole of $C{{O}_{2}}$ has a mass of 44 g, so, 1.5 moles of $C{{O}_{2}}$ has $\dfrac{44g\,C{{O}_{2}}}{1\,mole}\times 1.5\,mole$ = 66 g. One mole of any compound has the same number of atoms which are Avogadro numbers and has the value, $6.022\times {{10}^{23}}$ atoms.