Question

Calculate the molarity of 0.900 mol of Na, Sin 1.90 L of solution. molarity: .47 Calculate the molarity of 31.3 g of MgS in 913 mL of solution. molarity: 1 Enter numeric value 1 TOOLS X10'

Answer 1

Answer:

Explanation:

Molarity is defined to be the number of moles of solute divided by volume of solution ( in L).

i.e Molarity = number of moles of solute / volume of solution ( in L )

(a) Step 1: Calculation of molarity of Na₂S

Given, moles= 0.900 mol

and volume = 1.90 L

So, molarity = 0.900 mol / 1.90 L = 0.47 M

(b) Step 2: Calculation of molarity of MgS

We know, moles= mass given / molar mass = 31.3 g / 56.38 g/mol = 0.5552 mol

[ note: molar mass of MgS = 56.38 g /mol ]

and volume = 913 mL × (1 L / 1000 mL ) = 0.913 L [ note: 1 L = 1000 mL ]

So, molarity = 0.5552 mol / 0.913 L = 0.61 M