Question

if 5.85 grams of NaCl are dissolved in 90 grams of water the mole fraction of NaCl​

Answer 1

Answer:-

0.02

Explanation:-

• Molar mass of Sodium (Na) = 5.85g/mol

• Molar mass of Chlorine (Cl) = 35.5g/mol

• Molar mass of Hydrogen (H) = 1g/mol

• Molar mass of Oxygen (O) = 16g/mol

Hence, molar mass of NaCl :-

= 23+35.5

= 58.5g/mol

And, molar mass of water [H2O] :-

= 2×1+16

= 18g/mol

Number of mole in 5.85g of Nacl :-

= Given Mass/Molar mass

= 5.85/58.5

= 0.1 mole

Number of mole in 90g of water :-

= Given Mass/Molar mass

= 90/18

= 5 mole

Mole fraction of Nacl :-

= Mole of Nacl/Total mole in solution

= 0.1/[0.1+5]

= 0.1/5.1

= 0.02

Thus, mole fraction of Nacl is 0.02 .