Calculate the Molarity

1) 1.04 M

2) 4.02 M

We are given:

Number of Moles (n) = 0.65 moles

Volume of Solution (V) = 1.6 L

Solving for the Molarity:

We know that:

Molarity = nV

(where n is the number of moles and V is the volume of the solution in L)

replacing the variables

Molarity = 0.65 * 1.6

Molarity = 1.04 M

Hence, the Molarity is 1.04 M

We are given:

Volume of Solution = 825 mL OR 0.825 L

Mass of MgS = 28.7 grams

Number of Moles of MgS:

Number of moles = Given mass / Molar mass

Number of Moles = 28.7 / 56.38              [molar mass of MgS = 56.38 g/mol]

Number of Moles = 0.51 moles

Molarity of the Given solution:

We know that:

Molarity = nV  

[where n is the number of moles and V is the volume of the solution in L]

replacing the variables

Molarity = 0.51 * 0.825

Molarity = 0.42 M

Hence, the molarity is 0.42 M

in the given question, the partial pressure is calculated by using the ideal gas equation, that is, pv = nrt

here, p is pressure, v is volume = 25 l, n is number of moles = 0.0104 moles, r is gas constant = -0.0821 l.atm / mol.k

t is temperature = 273 k

p = nrt / v

p = (0.0104 mol × 0.0821 l.atm / mol.k × 273 k) / 25 l

= 0.0093 atm