Find the percent by mass in which 38.81 g of NaCl (58.45g/mol) is dissolved in 271.0 g of water.
To find the percent by mass of NaCl in the solution, we need to divide the mass of NaCl by the total mass of the solution (NaCl + water) and multiply by 100.
The mass of NaCl is given as 38.81 g.
The molar mass of NaCl is 58.45 g/mol.
The total mass of the solution is the mass of NaCl + mass of water
mass of water = 271.0 g
Total mass = 38.81 g + 271.0 g = 309.81 g
Percent by mass = (mass of NaCl / total mass) x 100
Percent by mass = (38.81 g / 309.81 g) x 100
Calculating this:
Percent by mass = 0.1255 x 100
Percent by mass = 12.55%
Therefore, the percent by mass of NaCl in the solution is 12.55%.