Question

Sodium bicarbonate breaks down on heating:
$2NaHC{{O}_{3}}\to N{{a}_{2}}C{{O}_{3}}+{{H}_{2}}O+C{{O}_{2}}$
Atomic mass of Na=23, C=12, H=1, O=16
(i)How many moles of sodium bi carbonate are there in the equation?
(ii)What is the mass of sodium bicarbonate used in this equation?
(iii)How many moles of carbon dioxide are there in this equation?

Answer 1

Sodium bicarbonate is made up of sodium cation and bicarbonate anion. It is a white colour crystalline solid. It usually appears as a fine powder. It is salty in taste or an alkaline taste like washing soda. The natural mineral form of sodium bicarbonate is nahcolite.

Complete step by step solution:
(i) moles is defined as the unit of measurement for atoms, molecules or other particles. One mole of substance is equal to $6.023\times {{10}^{23}}$ atoms. One mole of substance is equal to 22400mL at STP. One mole of substance is equal to its molecular weight. In the equation to find the moles we need to balance the equation first and if the equation is balanced then we need to check the numeral present at the side of the compound. That numeral is the number of moles which is used of that substance in reaction.
So here two moles of sodium bicarbonate are used in the equation.
(ii) as we know one mole of substance is equal to the molecular weight of the substance. So first we have to find the molecular weight of sodium bicarbonate. To find the molecular weight we need to see how many atoms are present in the compound. There is 1 sodium atom of 23g/mol weight. There is 1 hydrogen atom of 1g/mol. There is 1 carbon atom of 12g/mol. There are 3 oxygen atoms of 16g/mol. So the total weight of oxygen in the molecule is $16\times 3=48g/mol$.
So now we will add all the weight to find total weight of the molecule= $23+1+12+48=84g/mol$
So I mole of sodium bicarbonate = 84g/mol
As there are 2 moles of sodium bicarbonate used in reaction so,
2 moles of sodium bicarbonate = $84\times 2=168g/mol$
So the mass of sodium bicarbonate used in this equation is 168g/mol.
(iii) the moles of carbon dioxide used in the equation is 1. as I told you earlier that the numeral written after balancing the equation at the side of the molecule that numeral is its moles used in reaction.

Note: sodium bicarbonate is used as an antacid. It is used to give relief to heartburn and indigestion. It is used in formation of blood and to make urine less acidic. It can also cause swelling, muscle spasms and metabolic alkalosis.