StraightScience

In this video we look at the electrical conductivity of many difference substances by checking to see if an electrical current can flow through it and light up a light bulb. Remember that electrolytes have ions in the solution, and are thus able to have electricity flow through it. To simplify: strong electrolytes have a lot of ions, so the lightbulb should light up and be very bright. Weak electrolytes have few ions, so the lightbulb should light up but be dim. Nonelectrolytes have no ions, so the lightbulb should not light up. Make your observations!

Okay! In this video we look at how to increase the RATE a solute dissolves into a solvent. Please make sure you understand that the only thing we are affecting is how fast the solute dissolves, NOT how much solute dissolves. If you want to see how much solute will dissolve, check out the solubility curve. If you want to understand how to get a solute to dissolve faster, watch on. There are three ways increase the rate of dissolving: 1. Increase the Surface Area - individual grains of a solute will dissolve faster than a giant cube of the solute because the water molecules are actually able to surround the solute particles. The more surface area a solute has (the smaller the particles) the faster it will dissolve. 2. Stir the Solution - If you stir the solution, you are causing the solute and solvent particles to move faster and collide with each other more often. If a solvent and solute collide more often and at a higher speed, the likelihood that the solute will dissolve in that solvent is increased. 3. Increase the Temperature - Temperature is just a measurement of the kinetic energy of a substance (how fast the particles are moving). If you increase the temperature of a substance, the kinetic energy is increased, meaning that those particles are moving faster. If you increase the temperature of a solution, the solvent and solute particles are moving much faster. This means they are colliding into each other more often and faster, making the solute dissolve faster into that solvent. Good luck!

This video is about the 3 equations you need to memorize to solve problems dealing with pH.

In this video we look at how to calculate the molarity of a solution when you are given the mass percent and density of that solution. Not too difficult once you see how to do it. I personally like to solve for the moles and then the liters of the solution separately, but you can also just solve for molarity in one giant line of conversions. We look at both ways to solve. Be sure to watch your units, and good luck!

In this video we go over the combined gas law - which is not hard at all. It is appropriately names as it combines Boyle's, Charles' and Gay-Lussac's laws all into one equation: (P1)(V1) / (T1) = (P2)(V2) / (T2) Just watch your units and double check your math. You got this!

Naming covalent molecules is easy - you just need to know your prefixes! 1 - mono 2 - di 3 - tri 4 - tetra 5 - penta 6 - hexa 7 - hepta 8 - octa 9 - nona 10 - deca

We look at two different questions to solve for the concentration of a solution in mass-volume percent. This is a very common way to notate concentration for medications, so it's really important that you know how to solve this.

In this video we take a quick look at how to make sure you're getting whole number ratios in your empirical formulas and what to do if you get a decimal. Good luck!

In this video we go through 2 examples of volume percent calculations to see how much alcohol is in a 12.0 oz beer and a 2.0 oz pour of liquor. The equation for volume percent is: Volume percent = (solute volume) / (total volume) x 100 Just be sure to watch your units. If the solute volume is in mL and the total solution volume is in L, you'll have to convert so that they are BOTH in the same units before calculating. Good luck!