Calculate the molality and mole fraction of water, respectively, of a solution that is made by dissolving 3.50 g of potassium nitrate in 50.0 g of water. the final volume of the solution is 56.0 ml.

Answer : The molality of the solution is 0.692m. The mole fraction of water is 0.988.

Explanation :

Molality :

The molality of a solution is calculated as,

Step 1 : Find moles of Potassium Nitrate KNO₃.

Molar mass of KNO₃ is 101.1 g/mol

Mass of KNO₃ is 3.50 g

Step 2 : Find kg of the solvent

Water is solvent here.

Mass of water = 50.0 g = 0.050 kg

Step 3 : Use molality formula

Let us use these values to find molality of the solution.

The molality of the solution is 0.692 m

Mole fraction :

The mole fraction of a component of a mixture is calculated as,

Step 1 : Find moles of water

Let us find moles of water using the mole formula

Molar mass of water is 18.02 g/mol

Step 2 : Use mole fraction formula

Mole fraction of H₂O =

Mole fraction of H₂O is 0.988

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6