 So as part of your next set of labs, you'll be required to make varying solutions and basically a solution is a homogenous mixture of substances. So solutions can be made up of solids and liquids combined with each other or liquids and liquids combined with each other to make a solution. So why do you need to make up solutions? If you are going to research, for example, if you're going to be a research technician, your PI or your boss may require you to make up a particular solution. You need to know how they can be written in different ways and as a result interpret what is being required, how to make up a particular solution. So we're going to use some examples that you will also come across when you're doing your experiments to help you to understand how you make up your calculations to make sure you add the right amount of substances when making your solutions. So first, we're going to be talking about two basic types of solutions. There are others, other representations of solutions, but the ones that we'll focus on for your set of experiments are percentage solutions and molar solutions. So these are the two I'm going to be talking about right now. So an example of a percent solution would be, for example, make up a six percent solution of sucrose. Sucrose is a sugar. So in this case, because sucrose is also a solid, we have the actual sugar crystals of sucrose. So we call this type of percentage solution a weight per volume solution. So it's a weight per volume percentage solution. That means if you're going to make up a six percent sucrose solution, if you're making a hundred mils of this solution, it means that you're going to dissolve six grams of sucrose and you're going to bring the volume up. So it's six grams of sucrose to 100 mils of water. So we're using water as our solvent in this case. So sucrose is our solute and water is our solvent. So this is basically what is meant if you see the directions make up a six percent solution of sucrose. You're going to add six grams of, dissolve six grams of sucrose in water and bring the volume up to 100 mils. That's basically what you're going to do. Now you may see your requirements written in this form. This is another way in which you can write the concentration of solutions. This in this case, this would be a molar solution. So two molar sodium chloride is basically a solution that contains two moles of sodium chloride per liter of your solution. So it's two moles per liter of sodium chloride. So I am going to now go into exactly how you're going to come up with the calculations for obtain a solution of a specific volume and a specific percentage and we're going to also calculate how you actually will determine how many grams of sodium chloride you will need to make up a solution with a particular volume.