Question

Calculate the molar mass of NaHCO3(s), Na2CO3(s), and CO2(g) Calculate the number of moles of HCl contained in the two volumes of HCl solution (25.0ml and 50.0mL: remember to use the molarity of the solution rather than the molar mass of HCl to find molarity).

Answer 1

Maolar mass is calculated by adding atomic weights of the constituent atom and multily with the number atoms in case of more than one.

Molar Mass of NaHCO3 = 23 +1 +12+3x16 g/mol= 84 g/mol

Molar mass of Na2CO3 = 2*23+12+3*16 g/mol = 106 g/mol

Moalr mass of CO2 = 12 +2*16 =44 g/mol

Considering the molarity of the given solution of HCl = 1,

So, 1000 ml contains 1 mole.

number of moles in 25 ml solution = 25*1/1000 moles = 0.025 moles.

In 50 ml 1 M HCl solution, moles oh HCl = 50/1000 = 0.050 moles.