Question

Calculate the molecular mass of the baking powder.
A. $NaHC{O_2} = 68gmo{l^{ - 1}}$
B. $N{a_2}HC{O_3} = 107gmo{l^{ - 1}}$
C. $NaHC{O_3} = 84gmo{l^{ - 1}}$
D. None of these

Answer 1

Hint: The atomic masses of sodium, hydrogen, carbon and oxygen are $23gmo{l^{ - 1}}$,$1gmo{l^{ - 1}}$,$12gmo{l^{ - 1}}$ and $16gmo{l^{ - 1}}$ respectively.

Complete step by step answer:
The molecular mass is the total mass of the molecule. It is expressed in Daltons$\left( {Da\,or\,u} \right)$. Molecular masses are calculated using the atomic masses of constituent elements.
The whole molecular mass is determined by adding all the molecular mass of all the constituents.
For example,
In case of water $\left( {{H_2}O} \right)$,we have 2 hydrogen atoms and one oxygen atom.
Atomic mass of hydrogen$ = 1gmo{l^{ - 1}}$
Atomic masses of oxygen=$ 16gmo{l^{ - 1}}$
So, the molecular mass of water,
$\begin{array}{l}
 = 2 \times H\,atomic\,mass + atomic\,mass\,O\\
 = \left( {2 \times 1 + 16} \right)gmo{l^{ - 1}}\\
 = 18gmo{l^{ - 1}}
\end{array}$
Baking powder has a chemical formula $NaHC{O_3}$ and the chemical name is sodium hydrogen carbonate.
So, the molecular mass,$\begin{array}{l}
 = atomic\,mass\,of\,Na + 1 \times atomic\,mass\,of\,H + 1 \times atomic\,mass\,of\,C + 3 \times atomic\,mass\,of\,Na\\
 = 23 + 1 \times 1 + 1 \times 12 + 3 \times 16\,gmo{l^{ - 1}}\\
 = 84\,gmo{l^{ - 1}}
\end{array}$
Baking powder is a salt formed by sodium cation and a bicarbonate anion. It is amphoteric in nature but its aqueous solution is slightly basic due to the formation of hydroxide ions.
It has a wide range of applications in our daily life. Baking powder is used in the treatment of acidity in the stomach. Baking powder is also used to clean out the mouth as it contains antibacterial and anti-microbial properties. Baking powder is also used in deodorant to eliminate the smell of sweat.

So, the correct answer is “Option C”.


Note:
Baking Soda is only sodium carbonate. To start its functioning, it needs the acid and liquid while in case baking powder only liquid is required. Since baking powder contains both sodium carbonate and acid. The first working Baking powder is manufactured by Alfred Bird in England.