 Tell what the pH is for acids, bases, & neutrals.  Describe the basic differences between acids & bases. What do you think the letters “pH” stands for? potential hydrogen

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WHAT IS AN “ACID”? An acid is a substance that tastes sour. Citrus fruit such as lemons, grapefruits, oranges, and limes are acidic.

Acids react with certain metals such as magnesium, zinc, and iron to produce gases. When they react, the metals seem to disappear in the solution. This is why acids are described as corrosive, meaning they “eat away” at other materials. Hydrochloric acid eats away at the metal, forming bubbles.

Bases have properties such as a bitter taste and feels slippery when you touch them.

Visit the following websites to explore and learn about pH. Worksheet Activity Worksheet Activity Activity 3 (Use online lab journal & back of worksheet)

Read What is pH? Answer the 10 question on your own paper using complete sentences. (Also tell which paragraph your answer came from.)

1. What causes a substance to be acidic? 2. What causes a substance to be basic? 3. Why is water neutral? 4. If you have acid indigestion why does antacid help you feel better? 5. What is an indicator? A substance is considered to be an acid when it has many hydrogen atoms. (pH is between 1 and 6.9) A substance is considered to be basic when it contain a combination of hydrogen and oxygen atoms called hydroxyl groups. (pH is between 7.1 and 14) Water is neutral because it has an equal number of hydrogen (H) and hydroxyl (OH) groups. ( pH of 7) (Sections 2) (Section 3) Antacids make you feel better because they are a base and they help raise the pH of your acid stomach towards neutral. (Section 4) An indicator is used to test the pH of a substance. (Section 5)

6. Give three examples of indicators: 7. Why should you brush your teeth more than once daily? 8. What is another word for basic substances ? 9. How many times more acidic is a pH 4 compared to pH 7 ? 10. What question(s) do you still have about pH ? Examples of indicators are litmus paper, Bromothymol blue, grape juice, cabbage juice, and some purple flowers. (Sections 5& 6) You should brush your teeth more than once daily because the base toothpaste neutralizes the mouth and kills the bacteria that causes cavities, but soon the effect wears off and the bacteria return. (Section 4) Another word for a basic substance is alkaline. (Section 3) A pH 4 is 1000 times more acidic than pH 7 because the pH scale changes by powers of ten. (Section 5)

Vocabulary Copy the definitions below into your vocabulary section. (*Purple part goes in 3rd box) pH: potential of hydrogen Acids: A substance that contains many hydrogen ions, a pH lower than 7.0. Bases: A substance that contains many hydroxyl groups, has a pH higher than 7.0 Hydroxyl Groups: An oxygen atom combined with a hydrogen atom pH Indicators: Tells the pH of a substance by turning colors. Examples: litmus paper, cabbage juice, electronic test meters.

The pH Scale BrainPOP | pH Scale

Acids & Bases

BrainPop Activity AcidBaseNeutral Dissolves Metal Slippery Bitter Tastes Sour Releases OH- Releases H+ Lemons Soap NaCl (Salt) H O 2

Discovery Education Natural Acids & Bases The pH in the Chemistry of Nature

Interactive pH websites Acids, Alkalis and Neutralisation Choose: Universal Indicator Reactions 1st make predictions, then test substances /1fokv/syrer_og_baser/indledning_pH.s wfhttp:// /1fokv/syrer_og_baser/indledning_pH.s wf

Fill-in-the-Blank Complete the “Acids & Alkalis in Our Daily Lives” worksheet (On back of BrainPop Activity worksheet) as you fill-in- the-blanks at the following link: Acids and Alkalis in Our Daily Lives When you’re finished try these fill-in-the-blanks online: –Use of IndicatorsUse of Indicators –NeutralisationNeutralisation –AcidsAcids –Strong AcidsStrong Acids –Faces of science:: Do You Know Your Bubbles?Faces of science:: Do You Know Your Bubbles? (After filling in bubbles, click NEXT one time)

Movie: Acids & Bases Acids And Bases Movie - Free Educational Movies - The KidsKnowIt NetworkAcids And Bases Movie - Free Educational Movies - The KidsKnowIt Network