Acids and bases- how acidic are they? 11/4/17

https://upload.wikimedia.org/wikipedia/commons/2/23/216_pH_Scale-01.jpg

Last week, we learned:

• What a precipitate is
• What a catalyst is
• How to classify chemical reactions

This week, we will learn a bit more about acids and bases. And the pH scale. We learned a lot of these things last year, but we are recapping it.

WHAT THEY ARE-ACIDS AND BASES

Acids and bases are just acids and bases. They are everyday things, and they have a certain acidity-the acids have high acidities depending on what they are, and the bases do too. What about water? Water is acidic?! Why doesn’t it burn me up when I drink it?? Well, water is neither an acid nor a base. We call these substances neutrals. More about that later. We use a little thing called the pH scale to determine how acidic or basic something is. Litmus paper is a thing like that as well, but it only tells you whether the substance is an acid or a base and not how acidic it is.

pH SCALE-WHAT IT IS AND HOW IT’S USED

The pH scale is a way of determining the acidity of something. The numbers go from 1-14. The colors- Oh, well, I’ll show you…

ACIDS-WHAT ARE THEY?

Acids are acidic. That is how we describe them. I know, it may seem obvious, I mean the word acid is literally in the name, but acids are pretty cool. Let’s learn a bit more about them.

On the pH scale, an acid is less than pH 7. In other words, the reds, oranges, and yellows on the scale. The lower the number, the more acidic they are. pH 1 is extremely acidic, about the acidity of hydrochloric acid. pH six is about the acidity of urine or saliva. That’s the yellow. Everything in between… oh, well, later on there will be a more detailed one. On a piece of litmus paper, if you put it in an acid, the paper would turn red. That’s how it is with acids. They turn the paper and the indicator red. Speaking of indicator, we used it in our experiments. Universal indicator shows you if the substance is an acid or a base. For example, you place three drops of indicator in a small bowl. Then you pour three drops of, say, vinegar. We know vinegar is acidic, but let’s pretend you don’t. You watch as the mixture turns a pinkish-orange color. You can test the color against the pH scale to find out how acidic the vinegar was.

BASES-WHAT ARE THEY?

Bases are basic. Same as acids, that is obvious, because the word base is literally in the name. But bases are pretty much the opposite of acids. Let’s look deeper.

To be considered a base, the mixture of universal indicator and your substance has to be dark green, blue, or purple. Let’s say you added ammonia solution. Ammonia is basic, about an 11 on the scale, so the indicator would turn purplish. Same as acids, you can pour them on litmus paper. Same as acids, the paper only tells you i the solution is acidic, basic, or neutral. If the solution was basic, then you would see the litmus paper turn blue. Examples of bases are bleach, soapy water, cleaning supplies,milk of magnesia, baking soda, and sea water. Eggs are also basic. You can look it up anywhere. Substances are either acidic, basic or neutral, so it has to be one of them.

THE PROCESS OF NEUTRALIZATION

First things first, we need to discuss what a neutral substance is before we get into neutralization. A neutral is a substance that is neither acidic nor basic. It is neutral. If acids turn litmus paper red, and bases turn it blue, it doesn’t take a genius to figure out that neutrals don’t change the color. The color of litmus paper is purple. An excellent example of a neutral is water. Pure, healthy water is a neutral. It is not basic, and it is not burn-your-tongue-out acidic either.  

What happens if you mix together an acid and a base? Does it matter the strength of the acid, or the basicness of the base? What happens? Well, whenever you mix together an acid and a base, you will ALWAYS, ALWAYS, ALWAYS, ALWAYS get some type of salt (which is also a neutral. ALWAYS.) and water. ALWAYS. NO MATTER WHAT. Any type of neutralization reaction will always be a double displacement reaction. Remember the types? Here are some examples of neutralization reactions.

Basically, adding an acid and a base makes a neutral. Pretty easy to remember. If you remember the simple facts about acids and bases, you’re good to go. Let’s recap:

• Acids make litmus paper red; bases make it blue; neutrals make it purple.
• Acids are less than 7, bases are more than 7, and neutrals are 7 on the pH scale.
• All neutralization reactions are double displacements (remember Ethan, Grace, Brianna, and William!).
• Adding an acid and a base makes salt and water.
• All salts are neutrals.

S&EP: SP4: Analyzing and interpreting data

This week, we were discovering acids and bases while experimenting. We had a page to graph our discoveries and place them in a table. We would add different amounts of substances inside the testing plates and add indicator. We had to discover the reactions, and we had to analyze the data after we collected it.

XCC: Stability and Change

This week, we got to see the colors of the substances change. A lot of things changed about them, the color, sometimes the substance they were. Once, we even had to blow carbon dioxide into the indicator mixture to make it a neutral instead of an acid. That was fun to watch, the colors getting lighter and lighter until they were a light green. It was fun to watch until I got cross eyed-I was the one blowing.