Question

How many moles and how many grams of sodium chloride are present in 250 cm3 of a 0.500 m nacl solution?

Answer 1

Answer:

Explanation:

Given Molarity = 0.500 M

Volume of the solution = 250 cm³ = 0.250 L

Molarity is defined as the number of moles of solute present in one Liter of the solution. Mathematically,

Molarity = Number of moles of solute/ Volume of solution (L)

Putting numerical values,

⇒0.5 = Number of moles of solute/0.250

⇒Number of moles of solute = 0.5 x 0.250 = 0. 125 moles

Thus, number of moles of sodium chloride = 0.125 moles

Mass of sodium chloride = Number of moles x molar mass

                                           = 0.125 x 58.5 g

                                           = 7.1325 g

Answer 2

Answer:

M = 0.5

v = 250cc

total mass = 58.5

given mass = ?

M = given mass × 1000/total mass × v(cc)

0.5 = given mass × 1000/58.5 × 250

0.5 × 58.5 × 250/1000 = given mass

7.3125g = given mass

Mole

mole = given mass/molar mass

mole = 7.31/58.5

mole = 0.125 mol