Ways of Expressing Concentration of Solutions PDF

Ways of Expressing Concentration of Solutions Concentration is the measure of how much of a given substance is mixed with another substance. Solutions are said to be dilute or When we say that vinegar is 5% acetic acid in water, we are giving the concentration. If we say that th...

Ways of Expressing Concentration of Solutions Concentration is the measure of how much of a given substance is mixed with another substance. Solutions are said to be dilute or When we say that vinegar is 5% acetic acid in water, we are giving the concentration. If we say that the mixture has 10% acetic acid, this would be more concentrated than The solution on the left is more concentrated than the solution on the right because there is a greater ratio of solute (red balls) than solvent (blue balls) particles. The solution particles are closer together. The solution on the right is more A concentrated solution is one in which there is a large amount of solute in a given amount of solvent. A dilute solution is one in which there is a small amount of solute in a given  Two components of a Solution The solute and the solvent dissolve in each other. The component present in a small amount is called the solute. The particles of solute are dissolved in a solution while the solvent is the component present in a greater amount. For example, at 30°C, you added 30 g of table salt in 100 mL water. Your solute is the 30 g table salt and your solvent is 100 mL water. The terms "concentrated" and "dilute" provide qualitative methods of describing concentration.  Various Methods of Calculating Concentration of Molarity Solutions Molality Percent by Mass Percent by Volume Mole fraction Parts Per Million If your sink becomes clogged, you might buy a bottle of drain opener whose label states that it is a 2.4% sodium hydroxide solution. This means that the bottle contains 2.4 g of NaOH for every 100 g of solution. How to solve percentage concentration by mass problem Sample problem 1: Pure gold is referred to as 24 karats. Jewelry that is said to be 18 karats contains 18 g of gold for every 24 g of the material, the remaining 6 g consist of the other metal like copper or silver. ANALYZE: What is given in the problem? The mass of solute and the mass of solution? What are you asked to find? The concentration of the solution expressed as a percentage by mass Sample problem 2: What is the percentage by mass (% by mass) of a solution made by dissolving 0.49 g of potassium sulfate in 12.70 g of water? ANALYZE: What is given in the problem? The mass of solute and the mass of solvent What are you asked to find? The concentration of the solution expressed as a percentage by mass Example 3: In a solution prepared by dissolving 24g of Sodium Chloride (NaCl) in 152g of water, what is the mass percent of Sodium Chloride (NaCl)? Solution: First, identify the given. Given: Solute = 24g of NaCl Solvent = 152g of Water Second, identify the unknown or what is being asked in the problem. Unknown = Percent by Mass of NaCl. Third, write the formula and calculate the unknown. Percent by Volume Percent by Volume or Volume Percent is a common expression used for expressing concentration. It is related to the molar concentration but the difference is that the volume percent is expressed with a denominator of 100. It is used for reporting the concentration of liquids and solutes in a solution. It is also called %V/V and it is always expressed as a percentage (%) and the units of the volume should be in mL. Percent by volume is also widely used in the pharmaceutical field for expressing the How to solve percentage concentration by volume problems Sample problem: Determine the volume/volume percent solution made by combining 25 mL of ethanol with enough water to produce 200 mL of the solution. ANALYZE: What is given in the problem? The volume of solute and the volume of solution What are you asked to find? The concentration of the solution expressed as a percentage by volume Sample problem: A solution is prepared by dissolving 90 mL of hydrogen peroxide in enough water to make 3000 mL of solution. Identify the concentration of the hydrogen peroxide solution. ANALYZE: What is given in the problem? The volume of solute and the volume of solution What are you asked to find? Parts per Million When the amount of solute is very small, as with trace impurities in water, concentration is often expressed in parts per million. PPM is a term used in chemistry to denote a very, very low concentration of a solution. One gram in 1000 ml is 1000 ppm and one-thousandth of a gram (0.001g) in 1000 ml is one ppm. Parts Per Million (ppm) is a measurement of the Second, identify the unknown or what is being asked in the problem. Second, identify the unknown or what is being asked in the problem. Unknown = Potassium dichromate in grams Third, write the formula and calculate the unknown. But in this case we have to derive THE END!!!