# Percent by Weight Formula

## Solutions and Percent Weight Change Formula

There are various features of solutions, including molarity, normality, molality, and percent by weight formula. Representation of solutions as a relative percentage concentration of solute in the given solution is one of the most popular and preferred methods, and it has various benefits. A solute is a minor component of the solution dissolved in solvent (the major part). The solute composition and the solution's composition are required to calculate the percentage by weight formula.

### Percent Weight Change Formula

Here are some ways in which the percent weight change formula is represented:

%v/v:

We express a solution's volume concentration as %v/v, also known as volume per volume; here, both solute and solvent in a solution are in liquid form. For example, 50ml sulphuric acid getting diluted in 50ml water is represented as sulphuric acid 50% v/v.

%w/w:

This percent by weight formula represents any solution expressed as %w/w, meaning weight by weight; here, we only consider the weight of any solution's components. For example: if 100g solution contains 30g HCl and 70g water, we express it as hydrochloric acid 30% w/w.

%w/v:

This percentage weight by volume formula is expressed as %w/v, meaning weight per volume, also known as m/v. For example: if we use 1g Potassium Iodide for making 100ml solution, it is represented as 1%w/v solution of KI.

### Defining Solution

A solution refers to a homogeneous mixture of two or many compounds with the particle size being lesser than 1nm.

## Common ways of describing the Solution

Solutions are commonly described in various ways, which are as follows:

1. ### Molarity –

It means the number of moles of substance per liter in the solution.

1. ### Normality –

It is the number of gram equivalents per liter volume of the solution.

1. ### Molality –

Molality is the number of solute moles per Kg of solution.

1. ### Percentage Concentration of Solute in any Solution (percentage weight by volume formula) –

The mass of solute in per ml volume of solution * 100. It is represented as follows:

(Mass of Solute(g) / Volume of Solution(ml) ) *100

### Conclusion

We represent all of the percentage types by making some slight changes to the standard method of calculating percent weight by volume, i.e., (solute's mass (g) / Solution volume (ml) ) *100. For calculating percent weight by weight, we take both numerator and denominator by their weight, and for calculating percent volume by volume, both are taken by their volumes.

Q1: Define Solute and Solvent in a Solution.

A1: A solute is a component that is in lower quantity and is dissolved in the solvent.

A solvent is in higher quantity which is used for dissolving the solute for a solution's formation.

For example: in the solution of tincture of Iodine (Iodine mixture in alcohol), Iodine is the solute, and alcohol is the solvent.

Q2: What are the Ways to represent the percent Weight Change Formula?

A2: Percent weight change formula can be represented using the following methods:

1. %v/v - In this method, only volumes of solute and solution are considered

2. %w/w - In this method, only weights of solute and solution are considered

3. %w/v - In this method, the weight of the solute is considered whereas the volume of the solution is considered.

Q3: Mention the most common Ways for describing a Solution.

A3: We can describe a solution in terms of its components by calculating the following:

1. Molarity

2. Normality

3. Molality

4. Percent by weight : %v/v, %w/w, %w/v