Question

Be sure to answer all parts.

Calculate the molarity of each of the following solutions:
(a) 28.5 g of ethanol (C2H5OH) in 4.50 x 102 mL of solution
M M
es
(b) 21.6 g of sucrose (C12H22011) in 67.0 mL of solution
M
(c) 6.65 g of sodium chloride (NaCl) in 96.2 mL of solution
M

Answer 1

Answer: The molarity of each of the given solutions is:

(a) 1.38 M

(b) 0.94 M

(c) 1.182 M

Step-by-step explanation:

Molarity is the number of moles of a substance present in liter of a solution.

And, moles is the mass of a substance divided by its molar mass.

(a) Moles of ethanol (molar mass = 46 g/mol) is as follows.

`Moles = (mass)/(molar mass)\\= (28.5 g)/(46 g/mol)\\= 0.619 mol`

Now, molarity of ethanol solution is as follows.

`Molarity = (moles)/(Volume (in L))\\= (0.619 mol)/(4.50 * 10^(2) * 10^(-3)L)\\= 1.38 M`

(b) Moles of sucrose (molar mass = 342.3 g/mol) is as follows.

`Moles = (mass)/(molar mass)\\= (21.6 g)/(342.3 g/mol)\\= 0.063 mol`

Now, molarity of sucrose solution is as follows.

`Molarity = (moles)/(Volume (in L))\\= (0.063 mol)/(0.067 L) (1 mL = 0.001 L)\\= 0.94 M`

(c) Moles of sodium chloride (molar mass = 58.44 g/mol) are as follows.

`Moles = (mass)/(molar mass)\\= (6.65 g)/(58.44 g/mol)\\= 0.114 mol`

Now, molarity of sodium chloride solution is as follows.

`Molarity = (moles)/(Volume (in L))\\= (0.114 mol)/(0.0962 L)\\= 1.182 M`

Thus, we can conclude that the molarity of each of the given solutions is:

(a) 1.38 M

(b) 0.94 M

(c) 1.182 M