Question

25.3g of Potassium nitrate was dissolved in 125 ml of water.what is the Molality of the solution (Density of water is 1g=1ml) ​

Answer 1

Answer:

To do that, use the density of water. 500.mL ⋅1.00 g1mL =500. g. Next, use the molar mass of the solute to determine how many moles are ...

2.71 mol kg−1 Explanation: As you know, the molality of a solution tells you the number of moles of solute present for every 1 kg of the solvent. ...  More

Step-by-step explanation:

Explanation:

As you know, the molality of a solution tells you the number of moles of solute present for every 1 kg of the solvent.

This means that the first thing that you need to do here is to figure out how many grams of water are present in your sample. To do that, use the density of water.

500.mL⋅1.00 g1mL=500. g

Next, use the molar mass of the solute to determine how many moles are present in the sample.

115g⋅1 mole NanO385.0g=1.353 moles NaNO3

So, you know that this solution will contain 1.353 moles of sodium nitrate, the solute, for 500. g of water, the solvent.

In order to find the molality of the solution, you must figure out how many moles of solute would be present for 1 kg=103 g of water.

103g water⋅1.353 moles NaNO3500.g water=2.706 moles NaNO3

You can thus say that the molality of the solution is equal to

molality−−−−−−−=2.706 mol kg−1≈2.71 mol kg−1−−−−−−−−−−−−

The answer is rounded to three sig figs.

So, you know that this solution will contain 2.71 moles of solute for every 1 kg of solvent.

Answer 2

Answer:

Step-by-step explanation: