If 5.85 g of NaCl are dissolved in 90 g of water, the mole fraction of NaCl is

Question

If 5.85 g of NaCl are dissolved in 90 g of water, the mole fraction of NaCl is (A) 0.1 (B) 0.01 (C) 0.2 (D) 0.0196

Tardigrade Admin · Accepted Answer

Given:- Mass of NaCl =5.85 g Mass of H 2 O =90 g Number of moles of NaCl =(5.85/58.5)=0.1 Number of moles of H 2 O =(90/18)=5 Mole fraction of solute =( n text solute / n text solute + n text solvent ) Mole fraction =(0.1/5+0.1) ⇒ X B =0.0196

Q. If 5.85 g of NaCl are dissolved in 90 g of water, the mole fraction of NaCl is

0.1

0.01

0.2

0.0196

Given:- Mass of NaCl=5.85g Mass of H2​O=90g Number of moles of NaCl=58.55.85​=0.1 Number of moles of H2​O=1890​=5 Mole fraction of solute =nsolute ​+nsolvent ​nsolute ​​ Mole fraction =5+0.10.1​ ⇒XB​=0.0196