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The concentration of lead nitrate Pb(NO3)2

in a 0.726 M solution is __________ molal. The
density of the solution is 1.202 g/mL.

User Blubber
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1 Answer

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Answer: The concentration of lead nitrate Pb(NO3)2 in a 0.726 M solution is 0.755 molal.

Step-by-step explanation:

Given:

The molar mass of Pb(NO3)2 is 331.2 g/mol

Assuming 1 litre of solution. This would equal 1202 g of solution

In the one litre of solution, you have 0.726 mol Pb(NO3)2

0.726 mol (331.2 g/mol) = 240.5 g Pb(NO3)2

Mass of water in 1 L of solution = 1202 g - 240.5 g = 961.5 g = 0.9615 kg

Molality = mols of solute / kg of solvent

= 0.726 mol / 0.9615 kg

= 0.755 m Pb(NO3)2

User Manish Sapariya
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