You are viewing the article How to Calculate Solution Concentration at Lassho.edu.vn you can quickly access the necessary information in the table of contents of the article below.
This article was co-written by Chris Hasegawa, PhD. Chris Hasegawa is a professor of science and dean of California State University, Monterey Bay. Professor Hasegawa often teaches students complex scientific concepts. He holds a bachelor’s degree in biochemistry, a master’s degree in education, and a teaching certificate from the University of California, Davis. He earned his doctorate in curriculum and education from the University of Oregon. Before becoming a professor, Hasegawa conducted biochemistry research in neuropharmacology at the National Institutes of Health. He also teaches physical and life sciences, serving as a teacher and administrator for schools in California, Oregon and Arizona.
There are 8 references cited in this article that you can see at the bottom of the page.
This article has been viewed 57,205 times.
In chemistry, the concentration of a solution is the amount of solute that is dissolved with another substance called the solvent. The basic formula for calculating solution concentration is C = m/V, where C is the concentration, m is the mass of the solute, and V is the total volume of the solution. If the solution has a low concentration, you can solve the calculation in parts per million (ppm) for ease of reading. In the lab, you may be asked to find the mp concentration, or molar concentration of a solution.
Steps
Use the mass-for-volume equation
- If the solute in use is a liquid, you can also calculate the mass using the density formula D = m/V, where m is the mass of the liquid and V is its volume. To find the mass, multiply the density of the liquid by the volume.
Tip: If you must use a scale, you need to subtract the weight of the liquid container, or your calculation will be wrong.
- If you don’t measure the volume yourself, you may have to convert the solute mass to volume using the density formula.
- For example, if the problem asked to find the concentration of 3.45 grams of salt in 2 liters of water, you would find the volume of salt using the density formula. Look up the density of salt in a textbook or online and solve the equation to find m. In this case, the density of the salt is 2.16 g/mL. The formula would be 2.16 g/mL = (3.45 g)/V. Multiplying each side by V, we have V(2.16 g/mL) = 3.45 g. Then we divide each side by 2.16 to find the volume, i.e. V = (3.45 g)/(2.16 g/mL) = 1.60 mL.
- Add the mass of the solute to the volume of the solvent. In this example, we have 2 L + 1.6 mL = 2,000 mL + 1.6 mL = 2,001.6 mL. You can leave the unit in mm or change it back to liters to get 2.002 L.
- In the example finding the concentration of 3.45 grams of salt in 2 liters of water, your equation would be C = (3.45 g)/(2.002 L) = 1.723 g/L.
- Some problems may require calculating concentrations in certain units. You must remember to convert units before entering the final formula.
Find the concentration in percent or parts per million
- If the solute is a liquid, you may need to calculate the mass using the formula D = m/V, where D is the density, m is the mass, and V is the volume of the liquid. You can look up the density of a liquid or go online and solve the equation to find the mass.
- For example, if you wanted to find the concentration of 10g of cocoa powder mixed with 1.2 liters of water, you would find the mass of the water using the density formula. The density of water is 1,000 g/L, so we have the equation 1,000 g/L = m/(1.2 L). Multiply each side of the equation by 1.2 L to calculate the mass in grams, so m = (1.2 L)(1,000 g/L) = 1,200 g. Add the mass of cocoa powder to get 1,210 g.
- In the above example, C = (10 g)/(1.210 g) = 0.00826.
- In this example, the percentage concentration of the solution is (0.00826)(100) = 0.826%.
- In the above example, ppm = (0.00826)(1,000,000) = 8,260 ppm.
Tip: Parts per million is often used for very low concentrations because it is easier to write and understand than percentages.
Calculate the concentration mp
- For example, if your solute was potassium hydroxide (KOH), you would find the atomic masses of potassium, oxygen, and hydrogen to add together. In this case, the mp mass is = 39 +16 + 1 = 56 g/mp.
- The mp concentration is mainly used when you know the chemical composition of the solute in use.
- For example, if you want to find the number of mp in 25g of potassium hydroxide (KOH), the equation here would be = (25 g)/(56 g/mp) = 0.45 mp.
- Convert the mass of solute to grams if it is not in grams.
- The number mp is used to represent the number of atoms in the solution.
- In this example, if 400 mL of water is used, you must divide by 1,000 to get 0.4 L.
- Skip this step if the solvent volume has been recorded in liters.
Tip: You don’t need to add up the volume of the solute because it’s usually negligible. If there is a marked change in volume after dissolving the solute with the solvent, you will use the total volume.
- In this example, M = (0.45 mp)/(0.4 L) = 1.125 M.
Advice
- In the laboratory, if you don’t know how much solute has been added to the solution, you can perform a titration test with other reactive chemicals. You need to learn how to balance chemical equations with stoichiometry.
This article was co-written by Chris Hasegawa, PhD. Chris Hasegawa is a professor of science and dean of California State University, Monterey Bay. Professor Hasegawa often teaches students complex scientific concepts. He holds a bachelor’s degree in biochemistry, a master’s degree in education, and a teaching certificate from the University of California, Davis. He earned his doctorate in curriculum and education from the University of Oregon. Before becoming a professor, Hasegawa conducted biochemistry research in neuropharmacology at the National Institutes of Health. He also teaches physical and life sciences, serving as a teacher and administrator for schools in California, Oregon and Arizona.
There are 8 references cited in this article that you can see at the bottom of the page.
This article has been viewed 57,205 times.
In chemistry, the concentration of a solution is the amount of solute that is dissolved with another substance called the solvent. The basic formula for calculating solution concentration is C = m/V, where C is the concentration, m is the mass of the solute, and V is the total volume of the solution. If the solution has a low concentration, you can solve the calculation in parts per million (ppm) for ease of reading. In the lab, you may be asked to find the mp concentration, or molar concentration of a solution.
Thank you for reading this post How to Calculate Solution Concentration at Lassho.edu.vn You can comment, see more related articles below and hope to help you with interesting information.
Related Search: