Question

How many grams of sodium are in $3$ moles of sodium carbonate?

Answer 1

To solve this question, first we need to recall the chemical formula of sodium carbonate. After we get to know the chemical formula of sodium carbonate, we have to remember its molecular weight. Later on, we need to find the individual weight of sodium in the compound. And then multiply the result by three to get the final required answer.

Formula: ${\text{mass}} = {\text{moles}} \times {\text{molar mass}}$

Complete step-by-step answer: We know that the chemical formula of sodium carbonate is $N{a_2}C{O_3}$
The molecular weight of sodium carbonate is $106 {\text{g mo}}{{\text{l}}^{{\text{ - 1}}}}$
This means that one mole of sodium carbonate has a molecular weight of $106 g$
The molecular weight of sodium is $23 g$
So, we can say that in one mole of sodium carbonate, there is $23{\text{ g}} \times 2 = 46{\text{ g}}$ of sodium
Then, according to the question, we need to find the weight of sodium in three moles of sodium carbonate.
We can do so by multiplying the weight of sodium in one mole of sodium carbonate by $3$
That is $46{\text{ g}} \times 3 = 138{\text{ g}}$
Hence, there are $138 {\text{g}}$of sodium in $3$ moles of sodium carbonate.

Additional Information:
The number $6.022 \times {10^{23}}$ is commonly referred to as the constant of Avogadro and is often denoted by the '${N_A}$' symbol. It is the number of entities in one mole of any substance. Atoms, molecules, monatomic/polyatomic ions, and other particles can be the fundamental entities (such as electrons) that can be represented in moles.

Note: Even one gram of a pure element is known to contain an enormous number of atoms when dealing with particles at an atomic (or molecular) level. This is where it is widely used to use the mole concept. It focuses primarily on the unit known as a mole, which is a very large number of particles counted. Molar mass of each element is unique.