Solutions

- Learn how to quickly memorize Concepts

Ideal and Non-ideal Solutions

Can you easily recall the conditions of ideal and non-ideal solutions? If yes, good work! And if not, do not worry. You just need to remember two words- "HIGH VOLTAGE"

On the basis of Raoult's law, liquid-liquid solutions are classified as "Ideal" and "Non-ideal", and they follow certain conditions.

Ideal Solution

There is no change in volume on mixing the two components, i.e, $△ H_{m i x i n g} = 0$
There is no change in the enthalpy when two components are mixed, i.e, $△ V_{m i x i n g} = 0$

Non-ideal Solution

When we mix sulphuric acid in water, the amount of heat generated is quite large, and a change in volume is observed. The solution formed is a non-ideal one. Now, the conditions for a non-ideal solution are-

$△ H_{m i x i n g} \neq = 0$
$△ V_{m i x i n g} \neq = 0$

Molarity and Molality

Do you often confuse between molarity and molality? This confusion arises when we fail to recall the definition and sometimes interchange them. Isn't it?

Both of these terms help in expressing the concentration of a solution, but in a different way. One of them describes the moles of a solute in relation to the mass of a solvent, while the other one defines the moles of a solute in relation to the volume of a solution.

Let's look at a trick to remember the difference!

"Molar" in "Molarity" is one of the large teeth at the back of our mouth. And this molar is surrounded by a fluid. And we all know fluid as a substance that flows, and so it is measured in litres! And litre is a unit to measure volume. So, next time whenever you see the term "Molarity", remember "Molar, and the fluid around it".

So, here we go! Molarity of a solution is defined as the number of moles of the solute dissolved per litre (or

d m^{3}

) of the solution. We believe, now, you can define molality. If molarity is defined in terms of volume, then molality has to be defined in terms of mass of solvent. Alright! Let's quickly look at the expressions of molarity and molality!

Hypertonic and Hypotonic Solutions

Many a time, I am confused with the two terms - "Hypertonic" and "Hypotonic". Do you feel the same way? Let me make it simple for you.

In hypertonic solutions, the solute concentration is greater on the outside of a cell when compared with the inside of a cell. Because of this, water leaves the cell and flows into the solution outside it.

To remember this, think of a super excited or hyper baby who is ready to rush out of a house.

Similarly, water rushes out of the cell in the case of hypertonic solutions.

Next, if the solute concentration in the solution is lower than in the cell, the solution is hypotonic. In this case, water flows inside the cell making it swell.

How do you remember this?

Think of it this way - the cell swells like the O in hypotonic.