In this section, we'll take a look at the calculations involved in logarithms as well as anti-log functions. Now, in Gen Chem, we learned that pH represents the negative log of the concentration of our hydronium ion, which could be written as H3O+ or H+. Eventually, we'll revisit this concept when talking about determining the pH of acidic and basic solutions. But first, we're going to introduce logarithms before we even get to acids and bases.
Now, when dealing with a number with a decimal point like the one below of 12.005, we refer to the portion to the left of the decimal point as the characteristic.
Then, the portion to the right of the decimal point is referred to as our mantissa. Knowing that will be incredibly important when we take a look at log functions as well as anti-log functions. We say, when taking the log of a number, the number of digits in the mantissa of your answer is equal to the number of significant figures in the problem. Knowing this, try to see if you can answer the example below where I'm giving you the log of different values and from that, determine what the final answer will be. Try and attempt this on your own.
If you get stuck, don't worry. Just click over to the next video where you'll see how I approach those two examples.