Presentation on theme: " Tell what the pH is for acids, bases, & neutrals. Describe the basic differences between acids & bases. pH 2, acid or a base? pH 10, acid or a base?"— Presentation transcript:
Tell what the pH is for acids, bases, & neutrals. Describe the basic differences between acids & bases. pH 2, acid or a base? pH 10, acid or a base?
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: Indicates the pH of a substance by turning a different color for each pH. Examples: litmus paper, cabbage juice, electronic test meters.
Discovery Education Natural Acids & Bases The pH in the Chemistry of Nature
BrainPop Activity AcidBaseNeutral Dissolves Metal Slippery Bitter Tastes Sour Releases OH- Releases H+ Lemons Soap NaCl (Salt) H O 2
Interactive pH websites Acids, Alkalis and Neutralisation Choose: Universal Indicator Reactions 1st make predictions, then test substances http://www.emu.dk/gsk/fag/fys/ckf/fase1 /1fokv/syrer_og_baser/indledning_pH.s wfhttp://www.emu.dk/gsk/fag/fys/ckf/fase1 /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)