Science Experiments How-Tos

How To: Use Hess's law in physical chemistry

In this free video science lesson from Internet pedagogical superstar Salman Khan, we learn how to use Hess's law. Whether you need help studying for that next big test or could just use a hand finishing your homework, you're sure to be well served by this video lesson. For more information, including detailed, step-by-step instructions, take a look.

How To: Balance a chemical equation easily

In this video, we learn how to balance a chemical equation. First, take a look at both sides of the equation and figure out how many atoms there are for both. Once you write this out, you will have an idea of how unbalanced it is. Now that you've done this, you need to think about how you can make the equation equal. Look at the first line and then see how many you have to add to one side to make both equal to each other. Then, go to the second line and do the same. When finished, you will ha...

How To: Follow three rules to balance chemical equations

In this video, we learn how to follow three rules to balance chemical equations. The first rule is that you need to start by balancing elements that appear in only one reactant and one product. The second rule is that you need to multiply through by common factors. You must retain equal numbers of atoms of each element on both sides of the equation. The third rule is: if an atom appear in elemental form on one side of the equation, save it for last. Going over the rules of how the balance the...

How To: Balance chemical equations

n this tutorial, we learn how to balance chemical equations. This is a straight-forward concept to balance out both sides of the equation of chemicals. To start, you will need to analyze how many atoms in each chemical you have on each side. Once you do this, you will need to find what you can multiply by on each side to make them equal to the other side. Once you do this and have equal atoms on each side, then the equation will be equal. Remember that you cant have a half of an atom, so that...

How To: Properly balance chemical equations

In this video, we learn how to properly balance chemical equations. You will see what substances are in each side of the equation. You will then need to count the atoms that are on each side of the chemical equation. Once you write down the number of atoms on each side, you will need to even them out. To do this, you need to change the coefficients within the equation. These change the total number of atoms inside of a chemical. Once you do this, you will add more to each atom present and the...

How To: Understand chemical change in chemistry

In this video we learn how to understand chemical change in Chemistry. When you start out, you must first figure out what your cathode and anode is in the equation. Then, read it out to find out if it's oxidized. Once you have this figured out, you can find the conditions of temperature you need to maintain the chemicals. You can figure this out b doing a basic equation for all of the chemicals. Fill this in with the correct information, then the answer will be done. Make sure you understand ...

How To: Balance an easy chemical equation

In this video, we learn how to balance an easy chemical equation. You can do your equation by testing it out with the actual chemicals. Watch and see what the reaction is as they start to mix together. To balance this reaction out, you will need to analyze the number of atoms that each element has on both sides of the equation. For it to be balanced, you must have the same number of products and reactants in the equation. You cannot create or destroy matter, you can only change its form, so r...

How To: Understand organic molecules in chemistry

In this video, we learn how to understand organic molecules in Chemistry. First, you will need to take a look at the chemicals that are inside of each of the different molecules. See how the molecules are made out and then see what number of different acids are inside of them. Once you learn this, you can see what the difference between this and other molecules are. This can all help you understand the beginning and end of what's inside of the molecules. If you aren't good at chemistry, you w...

How To: Practice balancing chemical equations

In this video, we learn how to practice balancing chemical equations. First, take a look at the first and second part of the equation. Write out how many atoms each of the elements has in it. Compare each of the sides to see what the difference is between them. Then, find the multiple of each of the elements until they are equal to each other. After you find this, continue to do this for all of the different elements in the equation. This will give you a balanced chemical equation when you ar...

How To: Balance chemical equations with ease

In this video, we learn how to balance chemical equations with ease. First, you will need to take down the equation and find out how it is formed and how much each of the chemicals are in it. Draw a diagram if you need to so you have a visual key. If you figure out how many of each of the chemicals are in the equation, then you will know how to balance it out. You will make sure that both the right and left have the same number of chemicals and mass. Balance this out by adding in more chemica...

How To: Balance chemical equations the right way

In this tutorial, we learn how to balance chemical equations. The first thing you want to do is to draw a graph and label one side reactants and the other side products. Go through each of the atoms that are in your equation on both sides. Write out how many atoms are in each chemical. Then, find a common multiple that will give you and equal amount on each side of the equation. Continue to do this same for all the chemicals in your equation, then when you are finished write it out. Now you w...

How To: Perform knee replacement surgery

In this video we learn how to perform knee replacement surgery. The knee joint is accessed with an incision. Then, a number of different surgical tools will be used to perform the procedure. The part of the knee joint is removed first with surgical saws. Then, the artificial joint is put back into the area. Once this part is secured with screws, an insert will be joined in with it to keep it in place. The artificial joint is checked for the last time, then sutures are used to closed the joint...

How To: Make a wheel spin with angular momentum & inertia

In this video, we learn how to make a wheel spin with angular momentum & inertia. You will need: a bicycle wheel, a lighter, and a couple of strings attached to the top of a deck. Now, take the bicycle wheel and hang it on the strings on both sides of the wheel. When you turn the wheel it will fall off of the strings. Start the wheel spinning again, then light one of the strings on fire. When you do this, the string will fall off but the wheel will keep on spinning while rotating. Do this exp...

How To: Balance chemical equations properly

In this video, we learn how to easily balance chemical equations. There are two sides of a chemical equation, both must be equal to get the proper reaction. To balance these out, first write out the number of atoms that is on each element on each side of the equation. After this, you will need to find the multiple between the matching elements. Once you find this, you will be able to balance out the equation for each of the elements. When you do this, you will have the same mass and atoms on ...

How To: Make sodium bromate & potassium meta-periodate

This video tutorial is in the Education category which will show you how to make sodium bromate and potassium meta-periodate. This experiment uses toxic chemicals and releases harmful gases. First you have to make a saturated sodium bromide. To this solution then add a small amount of potassium dichromate. The solution now becomes concentrated. Then make the circuit as shown in the video. You need a 3 - 5 ohm resistor in order to reduce the current. Then let the cell run for around 6 hours. S...

How To: Balance chemical equations using a teacher's guide

In this video we learn how to balance chemical equations using a teacher's guide. A chemical equation is a brief way of summarizing what happens inside of a chemical reaction. When you mix up two different chemicals, they will create new types of chemicals in the equation. You have to take these new chemicals into equation when you are trying to balance it out. The mass on both sides must be the same as well as the number of different chemicals on each side of the equation. Try out practice e...

How To: Describe chemical formulas

This is a video tutorial in the Education category where you are going to learn how to describe chemical formulas. A chemical formula represents the actual number of atoms of each element within a molecule. Different visual representations of molecules include the ball and stick three dimensional model, a line drawing that represents the structure in two dimensional terms, and a shorthand used by organic chemists. If a molecule has 4 green atoms and 2 orange atoms, the ratio of green to orang...

How To: Balance chemical equations properly

In this video we learn how to balance chemical equations properly. What is a chemical equation? It's a statement that uses a chemical formula to show identities and relative amounts of the substances involved in a chemical reaction. To balance an equation out you must have the same number of atoms on both sides of the chemical equation. Or, you must have the same amount of mass or matter on both of the sides. Once you have these balanced out so they are the same then you will have it complete...

How To: Check blood pressure

In this video we learn how to check blood pressure. First, ensure that the patient is relaxed the cuff is empty of all air. The arm should be held at the level of the heart. The doctor will then start to pump air into the cuff to inflate it. The doctor will do this until the pulse is not felt anymore. The pressure of the cuff will start to raise, then they will slowly reduce the air from the cuff. The doctor will listen to the flow of blood through the artery as the air is leaving the cuff. N...

How To: Understand polyatomic chemical formulas

This is a video tutorial in the Education category where you are going to learn how to understand polyatomic chemical formulas. When writing the formula using polyatomics, the same cross-over rule applies. 1st identify the metal and non-metal. Then you write the symbols, write the charges, cross-over the charges from top to bottom, remove the charge and simplify the numbers and remove the 1s. for example, iron (II) phospahate. The "ate" ending implies that phosphate is polyatomic. The symbol ...

How To: Balance chemical equations the fun way

In this video we learn how to balance chemical equations the fun way. First, remember that matter cannot be created or destroyed. Take two different types of chemicals and put them on opposite sides of the equation. If you have more mass on one side than the other, these will not balance out. Once you have equal amounts of mass on both of the sides, you will be able to balance the chemical equation. Remember this rule whenever you are balancing out chemical equations. Use visual markers to he...

How To: Easily balance a chemical equation

In this video, we learn how to easily balance a chemical equation. In a balanced equation, there should be the same number of atoms on both sides of it. There are no rules that explain how you get a balanced reaction from expression. First, start on the molecule or compound that is the most atomically complex. After you look at this, you can learn how to make the rest of the equation equal to each side. This is a complex process that you must walk through to figure out, but it will result in ...

How To: Balance a chemical equation step-by-step

This is a video tutorial in the Education category where you are going to learn how to balance a chemical equation step-by-step. The left side of the equation is called the reactants and the right side is the new products. What will be new products when silver nitrate reacts with ferric chloride? The left side will be written as Ag NO3 + Fe Cl. The valence of Ag is +1, NO3 is -1, Fe is +3 and Cl is -1. On the right side the silver cannot go with iron because both are positive. So, it will be ...

How To: Use high voltages using the Wimhurst machine

In this video, we learn how to use high voltages using the Wimhurst machine. First, you must have a spinning wheel, double ended brushes, collecting combs, leyden jars, adjustable electrodes, and small metal plates. Once you connect all these together, you will notice the brushes on either side are perpendicular to each other and the wheel spin in opposite directions. Spin the wheel and then listen to the sound it makes. The plate will then charge with different electrons and create positive ...

How To: Explore Density, Viscosity & Miscibility with a Colorful Layered Liquid Science Experiment

Ever wonder why Jupiter has those colored bands across its surface? Jupiter's enormous mass is made from an array of different liquids, and those fluids do not play well together because of their different makeup. All of the hydrogen- and helium-based fluids are thought not to be miscible, which means that they aren't homogeneous in nature, resulting in strikingly beautiful bands across the planet's surface. But what about viscosity and how that correlates to the development of planets? What ...

How To: Synthesize copper(II) carbonate & sodium bicarbonate

This actions is a video tutorial in the Education category where you are going to learn how to synthesize copper(II) carbonate & sodium bicarbonate. For this you will need copper sulphate which is available in root kill and sodium bicarb which is baking soda. Take 100g of copper sulphate and dissolve in about 400ml of water. Now take 69.27g of baking soda. Add baking soda very slowly and keep stirring the solution. You got to be very careful as the chemical reaction will produce lot of carbon...

How To: Make maganese heptoxide (permanganic acid)

This video tutorial is in the Education category which will show you how to make manganese heptoxide (permanganic acid). This procedure is extremely dangerous. Manganese heptoxide is an extremely powerful oxidizing agent. It has the ability to set fuels on fire from mere contact. Get an old dish and put a spatula full of potassium permanganate on it. Add a few drops of concentrated sulphuric acid. A green liquid is formed which is the manganese heptoxide. Now you can add any fuel like butanol...

How To: Make elemental sulfur (sulphur)

This video tutorial is in the Education category which will show you how to make elemental sulfur (sulphur). The chemicals you need are nitric acid and sodium thiosulphate. The reaction produces toxic SO2 gas so keep it coved with a watch glass. Put 12.9 grams of sodium thiosulphate in a beaker and dissolve it in minimum amount of water. Pour about 15ml of nitric acid in to the beaker. Let it sit in a warm place for a couple of hours and the sulphur will settle at the bottom of the beaker. Th...

How To: Bend and fuse glass over a flame

In this tutorial, we learn how to bend and fuse glass over a flame. First, you will need to have a Bunsen burner turned on with a high flame. After this, let the flame stay on for several seconds, then adjust the airflow for the flame so it doesn't go too high. Now, find glass and pick it up on the bottom with your hands. Stick the tip of the glass into the bottom part of the burner, where the flame is the hottest. The piece of glass will turn orange in color as it gets hotter and hotter. Onc...

How To: Test paint for the presence toxic lead

In this tutorial, we learn how to test paint for the presence toxic lead. You will first need to make up two solutions. One will need sodium sulfide and water mixed together in a small container. Then, add acidic acid and water into another container. Drop small amounts of the mixtures into containers, then add in the paint to the containers. Watch and see how the reaction of the paint is with the mixture. If you start to see a black reaction occur in the container, you will know that your pa...

How To: Change the physical properties of yellow sulfur

In this tutorial, we learn how to change the physical properties of yellow sulfur. First, take a heat proof water glass and add in 1 teaspoon of sulfur powder. After this, heat the glass on a low flame for a few minutes. After this, the sulfur will start to melt and turn a reddish color. Now, pour the sulfur into some cold water after it's all the way melted and watch the reaction that is occurring. Once cool, you will be able to pick up the sulfur from the water and play with it, although it...

How To: Understand chemistry & chemical change

This video tutorial is in the Education category which will show you how to understand chemistry and chemical change. The question here is 10g of Mg ribbon reacts with 0.15 mol decimeter cubed of hydrochloric acid at 25 degree Celsius. What is the balanced equation for this reaction? When magnesium reacts with hydrochloric acid, you will get magnesium chloride and hydrogen. So, the equation will be Mg + 2HCl = MgCl2 + H2. Mg is in group 2 of periodic table and has a valance of 2, whereas Cl i...

How To: Build a magnetic stirrer from computer parts

In this tutorial, we learn how to build a magnetic stirrer from computer parts. This is a simple thing to make, and is great if you are going to be mixing chemicals and don't want to get your hands dirty. First, you will need to create a wooden box with the top empty. Then, place a computer fan into the middle of the box and pin it down. Place a magnet from the hard drive in the middle of the fan, then place a stirring rod on the glass that will go on the top of the wooden box. Now you will b...