Question

What is the molar mass of sodium oxygen oxalate $N{a_2}{C_2}{O_4}$?

Answer 1

Hint : First check the number of atoms each element has in $N{a_2}{C_2}{O_4}$. Multiply the molar mass of each element by the total number of that element present in the compound. Finally, add up the mass obtained by multiplying to get the molar mass of $N{a_2}{C_2}{O_4}$.

Complete Step By Step Answer:
According to the chemical formula of sodium oxygen oxalate, there are two atoms of sodium, two atoms of carbon and four atoms of oxygen.
We know that the molar mass of sodium is $22.989gmo{l^{ - 1}}$. Since there are two atoms, we will multiply the molar mass of one sodium atom by $2$ to get a mass of $45.98gmo{l^{ - 1}}$.
The molar mass of one carbon atom is $12.01gmo{l^{ - 1}}$. Since there are two carbon atoms, we will multiply the molar mass of one carbon atom by $2$ to get a mass of $22.02gmo{l^{ - 1}}$.
The molar mass of one oxygen atom is $16gmo{l^{ - 1}}$. Since there are four oxygen atoms, we will multiply the molar mass of one oxygen atom by $4$ to get a mass of $64gmo{l^{ - 1}}$.
To get the molar mass of the complete compound, we will simply add up the individual masses that we obtained above.
Thus,
$45.98gmo{l^{ - 1}} + 24.02gmo{l^{ - 1}} + 64gmo{l^{ - 1}} = 134gmo{l^{ - 1}}$
Hence, the molar mass of sodium oxygen oxalate is $134gmo{l^{ - 1}}$.

Note :
If you do not remember the molar mass of any element, use a periodic table. You can also multiply the atomic number of an element by $2$ to get the molar mass of many elements. For example, the atomic number of oxygen is $8$. If we multiply it by $2$ then we will get $16$ which is the molar mass of oxygen. However, this might not always work, so it is better to learn the molar mass of a few basic elements.