Question

Calculate the molarity of the following solutions.

Part A

0.900 mole glucose in 0.450 L of a glucose solution

Express your answer with the appropriate units.

Part B

88.0 g of HCl in 3.00 L of a HCl solution

Express your answer with the appropriate units.

Part C

29.5 g of NaOH in 320. mL of a NaOH solution

Express your answer with the appropriate units.

Answer 1

A)

volume , V = 0.45 L

use:

Molarity,

M = number of mol / volume in L

= 0.9/0.45

= 2.0 M

Answer: 2.0 M

B)

Molar mass of HCl,

MM = 1*MM(H) + 1*MM(Cl)

= 1*1.008 + 1*35.45

= 36.458 g/mol

mass(HCl)= 88.0 g

use:

number of mol of HCl,

n = mass of HCl/molar mass of HCl

=(88 g)/(36.46 g/mol)

= 2.414 mol

volume , V = 3 L

use:

Molarity,

M = number of mol / volume in L

= 2.414/3

= 0.8046 M

Answer: 0.805 M

C)

Molar mass of NaOH,

MM = 1*MM(Na) + 1*MM(O) + 1*MM(H)

= 1*22.99 + 1*16.0 + 1*1.008

= 39.998 g/mol

mass(NaOH)= 29.5 g

use:

number of mol of NaOH,

n = mass of NaOH/molar mass of NaOH

=(29.5 g)/(40 g/mol)

= 0.7375 mol

volume , V = 3.2*10^2 mL

= 0.32 L

use:

Molarity,

M = number of mol / volume in L

= 0.7375/0.32

= 2.305 M

Answer: 2.30 M