Classic Chemistry: Colorize Colorless Liquids with "Black" Magic, AKA the Iodine Clock Reaction

Want to make boring old colorless water brighten up on command? Well, you can control the color of water with this little magic trick. Actually, it's not really magic, but a classic science experiment known commonly as the iodine clock reaction, which uses the reactions between water and chemicals to instantly colorize water, seemingly by command. You can use different colorless chemicals to produce different colors, and you can even make the color vanish to make the water clear again.

How To: Divide small numbers by big numbers

This is a mathematical educational video on how to divide a small number by a larger number. You are aware that it is easy to divide a larger number by a small number. For example, if you want to divide 379 by 9 it is easy to do so. But if you have to divide 9 by 379 it is a bit difficult. You have to add a zero and see if you can divide. You need to add one more zero so that you can divide 900 by 379. But you should know that the answer would start like this 0.0 as we have added 2 zeros alre...

How To: Isolate the sugar in a can of soda

In this video from ScienceOnTheBrain we learn how to isolate the sugar in a can of soda. To find out how much sugar is in soda, pour a can into a pot and boil it until all the water is gone. You will be left with the sugar, and then you can weigh it. First weigh your pot before pouring the soda in. Now boil the soda on the stovetop. When the water evaporates, you'll be left with a syrupy sugar. A can of soda has 39 grams of sugar in it. That equates to about 7 1/2 teaspoons. Fruit juice conta...

How To: Make hydrochloric acid from salt

In this tutorial, we learn how to make hydrochloric acid from salt. First, you will pour some salt into a distil flask. After this, you will add in some concentrated sulfuric acid to the salt. Next, you will let these react with each other. You will start to see gasses bubble up and the excess hydrogen chloride gas come out through the top of the tube. To create a stronger reaction, you can add heat underneath the reaction. Then, test this by exposing it to ammonium chloride. If it's the righ...

How To: Find the volume of a sphere with radius r

Are you slightly rusty on your math skills? This video demonstrates how to find the volume of a sphere with a given radius. The first step is to sketch a solid and cross-sectional view of your sphere to get an understanding of the process to come. Next, find a formula for the area of this cross-section. Third, find the limits of integration. This will allow you to take the area of each cross-section in the sphere, not just the singular one you are viewing. Lastly, integrate this formula from ...

How To: Find a number given Its percent

This how-to video is about how to find a number when its percent is given. This video is really helpful and effective in finding the number when the percent is given, the following steps are explained in the video to find the number when its percent is given:

How To: Find the area of an oblique triangle using formulas

In this tutorial the instructor shows how to find the area of an oblique triangle using different formulas. To find the area of an oblique triangle there are different formulae. The first formula to calculate the area of a triangle is area A = (1/2) * a * b * Sin(C), where a and b are the lengths of the two sides of the triangle and C is the value of the angle of the triangle that lies in between the two sides a, b. Now substitute these values in the given formula to find the area if you have...

How To: Tie off a suspension ring for rope bondage

If you're planning on doing some bondage knots, you better learn how to do it right. This video shows you how to properly tie off a titanium suspension ring for use in your bondage activities. This video is clear and straight forward, using a large piece of rope, making it easy to see exactly how it's done. Remember to be careful with your S&M knots, especially if you're suspending someone's weight.

How To: Find the standard deviation with the Z-Score formula

In this tutorial, we learn how to find the standard deviation with the Z-Score formula. First, take your problem and write it out one by one underneath each other. Then, you will need to substitute the numbers in for the variables that are in the problem. Once you do this, you will follow the basic rules of math to find out what the answer to the problem is appropriately. Once you have done this, finish off the problem to find the answer, then you will have found the standard deviation using ...

How To: Write a sum/difference of logarithms as a logarithm

To write the sum or difference of logarithms as a single logarithm, you will need to learn a few rules. The rules are ln AB = ln A + ln B. This is the addition rule. The multiplication rule of logarithm states that ln A/b = ln A - ln B. The third rule of logarithms that deals with exponents states that ln (M power r) = r * ln M. Using these three rules you can simplify any expression that involves logarithms to arrive at a single logarithm. The instructor shows how to apply these rules to a f...

How To: Calculate the area of a parallelogram

Calculating The Area Of A Parallelogram A parallelogram is a 4-sided shape formed by two pairs of parallel lines. Opposite sides are equal in length and opposite angles are equal in measure. To find the area of a parallelogram, multiply the base by the height. The formula is:

How To: Evaluate logarithms using a calculator TI-83

A video to help calculator users find the natural logarithm (log base e, or "ln") and standard logarithm (log base 10, or simply "log") of any number using a TI-83 calculator (works for any issue of the TI-83 calculator or even a TI-84 calculator). Turn on your calculator. To find the natural log of a number, press the "ln" button (the third button from the bottom left), enter the number you want to find the natural log of, press the ")" (closed parenthesis) button, then press enter. The same...

How To: Get your official SAT score from College Board online

The SATs are a very valuable college entrance test and could determine if you're accepted or denied to your favorite university. So, once you've learned to ace the SATs and have already taken your test, get your scores as soon as they're out! Don't sit in dreaded anticipation— go to College Board and get your SAT test results now!

How To: Empty a large water bottle in two seconds with a straw

Bottled-beer chuggers the world over already know that letting air into your beverage with a straw makes it pour faster into your mouth. Did you know, however, that the same technique can be modified and used to empty a fluid into another container (or onto the floor) even more quickly? This video will show you how to use a modified straw technique to introduce air into a large bottle of water or other drink bottle, causing the contents to empty at a torrid pace.

How To: Find the inverse of a function in algebra

Need a little help figuring out how to find the inverse of a function in algebra? Watch this free video lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this free math tutorial, you'll learn how to calculate the inverse of a given algebraic fun...

How To: Do normal probability calculations on a calculator

Probability computation is a complex process and even using a calculator can be difficult. But normal probability calculations can be performed quickly with the help of calculator once you know how to use it. So when you have to calculate a probability from a normal distribution you can use the functions on your scientific calculator. You can use the normal CDF function from you calculator to compute the area under a normal curve. The function requires lower band and upper band values, the me...

How To: Find the area of a circle with a given radius

This video describes how to find the area of a circle given a radius of 4cm. The video begins by describing the formulas needed to find the area of the circle. The narrator cautions the viewer on a few common mistakes that people frequently make while using these formulas, such as not properly squaring the radius of the circle. The solution to the formula for a 4cm radius is 50.24 cm^2. The video then demonstrates that this value makes sense by overlaying a grid onto the circle and visually s...

News: Reverse Arrow Trick - Amazing

When the arrow is moved to a particular distance behind the glass, it looks like it reversed itself. When light passes from one material to another, it can bend or refract. In the experiment that you just completed, light traveled from the air, through the glass, through the water, through the back of the glass, and then back through the air, before hitting the arrow. Anytime that light passes from one medium, or material, into another, it refracts.

How To: There's Metal Hiding in Your Pepto-Bismol and Here's How You Extract It

Got an upset stomach or a little heartburn? America's favorite pink pill will cure it right up. But did you know that there's actually metal hiding in those chewable Pepto-Bismol tablets? Yes, metal. Technically, it's a poor metal, but metal's metal, right? Well, we do tend to eat a lot of iron in our diets, because it carries oxygen throughout our bodies, so consuming metallic minerals isn't anything abnormal. But you'd never think that Pepto-Bismol is actually made up of metal.

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: Calculate the age of the universe w/ Hubble's constant

This is a great instructional video on how to calculate the age of Universe from Hubble's constant. The speed the galaxy moves away from us is directly proportional to the distance from us. Now think of big bang theory. Hubble's constant is equal to velocity over distance. 1 over Hubble's constant is equal to distance over velocity that is equal to time. Time equals to 1over 71. If you change it into all the same units words it is one over 71000 or 3.09x 10 to the power of 22. It is 3.09x10 t...

How To: Analyze cheap sulfuric acid for concentration & purity

In this home scientist video the instructor Robert Bruce talks about cheap sulfuric acid. He says that sulfuric acid is very important in any lab both as a reagent and a precursor for preparing other chemicals. He points to the battery acid saying that it is a good source of sulfuric acid which is 35% concentrated. Now he shows various methods to obtained sulfuric acid and shows how to test one of the thus obtained sulfuric acid for its concentration. In this video the author talks about sulf...

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