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What is the number of moles of NaHCO3in 250cm3 of its sol...

What is the number of moles of NaHCO3in 250cm3 of its solution if the solution contains 8.4 g of NaHCO3 in 1 dm3 of the solution. [Na = 23, 0 = 16, C = 12, H = 1)

A.

1

B.

0.25

C.

0.05

D.

0.025

E.

0.01

Correct answer is D

no of mole in 250\(cm^3\) of its solution is about molar concentration.

using n = cv 

c = \(\frac{n}{v}\)

where c = molar concentration, n = number of moles and v = volume in \(dm^3\)

number of mole of NaHCO3 = mass of NaHCO3 / molar mass of NaHCO3 = \(\frac{8.4}{84}\) = 0.1moles

but v = 250\(cm^3\) = 250/1000 = 0.25\(dm^3\)

therefore c = 0.25 x 0.1 = 0.025mol\(dm^3\)