Question

A chemist prepares a standard solution in the lab using a 500.0 mL volumetric flask. 4.865 g of NaCl is used. What is the molarity of the NaCl solution?

Answer 1

$\huge \underbrace \mathfrak{Answer}$

0.17 mol/l

Explanation:

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⠀⠀⠀⠀▨ Note

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• What is molarity?

Molarity is the amount of moles of component present in certain volume of solution.

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• What is mole?

Mole is a unit in chemistry i.e. 6.022×10²³ ions, atoms or molecules present in the substance.

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⠀⠀⠀⠀● Solution

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Weight of NaCl(m) = 4.865 grams

Volume(V) = 500ml = 0.5 liters

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1 mole of NaCl = 58g

So 4.865g of NaCl(n)

$= \sf \frac{4.865}{58} = 0.084 \: moles$

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While

$\frak{molarity = \frac{no \: of \: moles}{volume} }$

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Substituting the required values

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$\sf \implies molarity = \frac{n}{V} \\ \\ \sf \implies molarity = \frac{0.084}{0.5} \\ \\ \ \boxed{ \tt{ \implies molarity = 0.17 \: mol \: {l}^{ - 1} }}$