Question

If you had started with 2.60 grams of Na2CO3 and reacted it with excess of HCl, what mass of NaCl in grams would you expect to produce?

Answer 1

Molar mass of Na2CO3,

MM = 2*MM(Na) + 1*MM(C) + 3*MM(O)

= 2*22.99 + 1*12.01 + 3*16.0

= 105.99 g/mol

mass(Na2CO3)= 2.6 g

use:

number of mol of Na2CO3,

n = mass of Na2CO3/molar mass of Na2CO3

=(2.6 g)/(1.06*10^2 g/mol)

= 2.453*10^-2 mol

Balanced chemical equation is:

Na2CO3 + 2 HCl ---> 2 NaCl + H2O + CO2

Molar mass of NaCl,

MM = 1*MM(Na) + 1*MM(Cl)

= 1*22.99 + 1*35.45

= 58.44 g/mol

According to balanced equation

mol of NaCl formed = (2/1)* moles of Na2CO3

= (2/1)*0.0245

= 0.0491 mol

use:

mass of NaCl = number of mol * molar mass

= 4.906*10^-2*58.44

= 2.867 g

Answer: 2.87 g