Introduction to Mass Percent Formula
Mass percent is another method of expressing the composition of the solution mixture. It describes the amount of solute (grams) present in 100 gm of the solution. Let us look at the two commonly used formulas to find the mass percentage in a given question.
Case I:
You are asked to find out the mass percentage of an element in a compound, the formula used will be:
Case II:
The Formula for the mass of an element/compound in a solution/mixture
Example: Find the mass percentage of 6 g sodium hydroxide dissolved in 50 g of water. (Note: since the density of water is nearly 1, this type of question often gives the volume of water in millilitres.)
Solution of Mass Percent:
First, find the total mass of the solution:
total mass = 6 g sodium hydroxide + 50 g water total mass = 56 g
Now, you can find the mass percentage of the sodium hydroxide using the formula:
mass percent = (grams of solute / grams of solution) x 100 mass percent = (6 g NaOH / 56 g solution) x 100 mass percent = (0.1074) x 100 = 10.74% NaOH
Question: Find the masses of sodium chloride and water required to obtain 175 g of a 15% solution.
Options:
(a) NaCl = 26.25 gm; water = 147.75 g
(b) NaCl = 36.25 gm; water = 147.75 g
(c) NaCl = 26.25 gm; water = 167.75 g
(d) NaCl = 40.25 gm; water = 147.75 g
Answer: (a)
Solution: This problem is a bit different because it gives you the mass percentage and asks you to then find how much solute and solvent are needed to yield a total mass of 175 grams. Start with the usual equation and fill in the given information:
mass percent = (grams solute / grams solution) x 100 15% = (x grams sodium chloride / 175 g total) x 100
Solving for x will give you the amount of NaCl:
x = 15 x 175 / 100 x = 26.25 grams NaCl
So, now you know how much salt is needed. The solution consists of the sum of the amount of salt and water. Simply subtract the mass of salt from the solution to obtain the mass of water that is required:
mass of water = total mass - a mass of the salt mass of water = 175 g - 26.25 g mass of water = 147.75 g
Studying Mass Percent with Vedantu
If you're looking to study mass percent and learn how to apply the mass percent formula, you've come to the right place! On this page, you will find a large amount of information about the definition of mass percentage and how to solve it.
On Vedantu, you will always find the latest, up-to-date information about academics. There are also several study resources available for free for students to refer to. These study materials will help in enhancing your knowledge and practical skills. For example, when studying Chemistry, you can refer to a vast range of resources like syllabi, past papers, sample papers, important questions for the exam, revision notes, etc. All of these are free to download on Vedantu. You can also book one-on-one lessons with experts in the subject matter to learn more. You can also study the specific topic of Mass Percent from Vedantu.
Conclusion
Naturally, we also recommend that you refer to your textbooks, but for variation, you can also look up the various resources on Vedantu. To find some solved example questions on a mass percent, you can check here on Vedantu.
FAQs on Mass Percent Formula
1. What is Mass Percent?
Mass Percent is a term used to express the concentration of an element in a compound or any other component in a mixture. Mass percent is calculated by dividing the mass of the component by the total mass of the mixture and multiplying it by 100.
For example, if a mixture contains 4 different components, known as A, B, C, and D, and you need to find the mass percent of the component D. The way you would find out the mass percent of component D is by dividing the mass of D by the mass of the entire mixture and then multiplying it by 100.
2. How to Calculate Mass Percent?
Mass Percent is calculated by dividing the mass of the component or solute for which you're trying to find the mass percent by the total mass of the mixture or solution.
For example, let's say that you need to find the mass percent of 6 grams of sodium hydroxide which has been dissolved in 50 grams of water.
First, you would need to find the total mass of the solution, which is Sodium hydroxide 6 grams + Water 50 grams. So the total mass is 6+50 = 56 grams.
Next, you apply the formula, which is:
(Mass of component ÷ total mass of mixture) × 100
So in this case the equation is:
(6÷56)×100
(0.1074)×100 = 10.74%
3. How to study Chemistry Mass Percent?
To study for Mass Percent in Chemistry, there are two important things you need: a good study schedule and high-quality study materials. Vedantu's website offers the right study material in PDF format.
First, create a good study schedule that is spread out over a few weeks. This will give you enough time to absorb and retain the information, as it is proven that the human brain processes information better when it is spread out.
Next, gather the required materials to study mass percent. Your textbooks and this webpage are a good place to start. This page explains in simple terms what mass percent is and how to calculate it, while your textbooks will go more in-depth about the topic and probably provide practice questions as well.
4. Where can I find more study material for Mass Percent Chemistry?
You can find more resources to help in your studies on the Vedantu website or app. These materials are completely free to download to anyone with a Vedantu account. If you don't have a Vedantu account you can easily create one by signing up with your phone number or email address.
On this page, you will find a simple definition and explanation of the concept of mass percent along with the formula for calculating it. There are also simple examples given to illustrate how to use the formula. Apart from these materials, if you need more help in studying mass percentages, you can look through your textbooks and refer to the example questions and their answers provided on Vedantu.
5. Is there a practical example of Mass Percent?
To further illustrate how to calculate mass percent, let's look at a few examples. You already know from reading through this page that the formula for calculating mass percent is the mass of the solute/component divided by the total mass of the solution/mixture, which is then multiplied by 100.
(Mass of Solute ÷ Total Mass of Solution)×100
So let's take the example of finding the mass percent of 25g of sugar that has been dissolved in 100g of water.
First find the total mass, which is Sugar 25g + Water 100g = 125g.
Next, apply the formula.
(25g ÷ 125g) × 100
(0.2) × 100 = 20%
