How do you calculate molality?

How do i calculate the molality of a substance?

  • Answer:

    Molality (mol/kg, molal, or m) denotes the number of moles of solute per kilogram of solvent (not solution). So in your example you need to convert 25.0g of KBr to moles and 750.0mL to kg. Then divide. To convert g to mols - use atomic weights. To convert mL to kg, use the conversion given in the problem.

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Molality is the moles of solute (KBr) per kg of solvent (pure water). Just find how many moles 25.0g of KBr equals and divide that by the mass of water (0.750kg).

Dan

Molality (mol/kg, molal, or m) denotes the number of moles of solute per kilogram of solvent (not solution). So in your example you need to convert 25.0g of KBr to moles and 750.0mL to kg. Then divide. To convert g to mols - use atomic weights. To convert mL to kg, use the conversion given in the problem.

groma

molality is moles solute/kg solvent 119 g/mol is the molar mass of KBR Moles of solute = 25.0g/ 119 g/mol Moles of solute = .210 750 ml of water isi equal to 750 g of water, which is equal to .750 kg of water So divide the .210 mols/.750 kg for the molality of the solution, and you get .280 mols/kg. Hope this helps.

Vague

Molality is the moles of solute (KBr) per kg of solvent (pure water). Just find how many moles 25.0g of KBr equals and divide that by the mass of water (0.750kg).

Dan

molality is moles solute/kg solvent 119 g/mol is the molar mass of KBR Moles of solute = 25.0g/ 119 g/mol Moles of solute = .210 750 ml of water isi equal to 750 g of water, which is equal to .750 kg of water So divide the .210 mols/.750 kg for the molality of the solution, and you get .280 mols/kg. Hope this helps.

Vague

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