Question

A 90.00 mL solution of NaCl and ethyl alcohol has 7.83 g of salt dissolved in the alcohol. Calculate the molar concentration of the solution. Remember to use significant digit rules.

Answer 1

The  molar  concentration  of the solution  is calculated as  follows

find the moles of NaCl used  to  make the solution

moles =  mass/molar  mass
mass =7.83  g
molar  mass =58.5  g/mol
moles = 7.83 g/ 58.5 g/mol = 0.134 moles

molarity (  concentration  in mol/l) =  number  of moles/volume  in  liters

volume  in liters =  90ml/1000 =0.09  liters

molarity  is  therefore = 0.134  moles/0.09 L =1.49   M

Answer 2

Answer:

The  molar  concentration  of the solution  is calculated as  follows

find the moles of NaCl used  to  make the solution

moles =  mass/molar  mass

mass =7.83  g

molar  mass =58.5  g/mol

moles = 7.83 g/ 58.5 g/mol = 0.134 moles

molarity (  concentration  in mol/l) =  number  of moles/volume  in  liters

volume  in liters =  90ml/1000 =0.09  liters

molarity  is  therefore = 0.134  moles/0.09 L =1.49   M

Explanation: