Question

4. Assuming complete precipitation of AgCl, calculate the sum of the molar concentration of all the ions if 2 litre of 2 M Agso4 is mixed with 4 litre of 1 M NaCl solution. (A) 4M (B) 2 M (C) 3M (D) 2.5M​

Answer 1

Answer:

4M

Explanation:

To get a correct answer we must first write a correct balanced chemical equation

Ag2SO4 + 2NaCl —> 2AgCl + Na2SO4

We the proceed to finding the moles of the reactants

One mole = a thousand cubic centimetres

But here the volume has been given in litres

To convert litres to cubic centimetres

1 l = 1000 cm3

Therefore

4 l × 1000 = 4000 cm 3

2l × 1000 = 2000cm 3

Moles of silver sulphate

Moles  =  molarity × Volume /1000

2 × 2000 /1000 = 4 moles

Moles of sodium chloride

4000× 1/1000 = 4 moles

We shall use the moles of sodium chloride to determine the moles of silver chloride because it is the limiting factor

Their mole ratio is 2 : 2 therefore the moles of silver chloride are 4 moles.

Its molarity is 4M because it was completely precipitated.