Question

A reaction mixture is prepared by adding 100mL of solvent, 10 drops(0.5mL) of phenolphthalein, and 1.00mL of t-butyl chloride.

a) How many mol of t-butyl chloride are in the initial reaction mixture?

b)What is the initial concentration(in M) of t-butyl chloride in the mixture?

Answer 1

a)

volume of t-butyl chloride = 1.0 mL

density of t-butyl chloride = 0.840 g/mL

Mass of t-butyl chloride = volume x density =(1.0 mL) x (0.840 g/mL) = 0.84 g

Molar mass of t-butyl chloride = 92.57 g/mol

No. of mol of t-butyl chloride = mass /molar mass = (0.84 g)/(92.57 g/mol)

= 0.00907 mol

No. of mol of  t-butyl chloride in reaction mixture = 0.00907 mol

b)

No. of mol of t-butyl chloride = 0.00907 mol

Total volume of reaction mixture = 100 mL + 0.5 mL + 1.0 mL = 101.5 mL = 0.1015 L

Molarity (M) = No. of mol / volume (L)

Molarity (M) = (0.00907 mol)/(0.1015 L)

= 0.0894 mol/L

= 0.0894 M

Initial concentration of t-butyl chloride = 0.0894 M