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

Step-by-step explanation:

Answer 2

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