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1.
What does a soap or detergent do to help water wash away dirt and oil?
Soaps have a hydrophobic end that attaches to the dirt or oil, and a hydrophilic end that attaches to water. So when you rinse away the soapy/dirty water, the soap carries the dirt and oil with it.
2.
List some characteristics of an acid. A base? If you only have the chemical formula of a compound, how can you tell if it is an acid or a base?
Bases end with hydroxide Acids - always start with a Hydrogen
(ex. HCl, H
2
SO
4
)
- have a pH of less than 7
- taste sour
(ex. NaOH, Ba(OH)
2
- have a pH of greater than 7
- taste bitter
- react with some metals to produce H
2
gas - feel slippery
- can be neutralized with a base - can be neutralized with an acid
- turn blue litmus paper to pink
- turn bromothymol blue to yellow
- turn red litmus paper to blue
- turn phenolphthalein to pink
- conduct electricity when dissolved in H
2
O - conduct electricity when dissolved
3.
List some common substances that are acids and bases.
Acids: vinegar, citrus juices, club soda, tomatoes, ASA (aspirin) etc
Bases: baking soda, windex, antacid, Drano, ammonia, (lots of cleansers)
4.
What is an acid-base indicator? What 4 indicators are you required to remember, and what do they do?
Indicators detect the presence of another substance. They change color if the substance is present. We worked with acid/base indicators, which test for the presence of acid or bases. The ones I would like you to remember are:
BASE INDICATORS – phenolphthalein (turns pink) and red litmus paper (turns blue)
ACID INDICATORS – bromothymol blue (turns yellow) and blue litmus paper
(turns pink)
5.
What is a neutral compound? What is the pH of a neutral compound?
A neutral compound is neither acidic or basic. It has a pH of 7, which means that the number of Hydrogen ions is equal to the number of Hydroxide (OH) ions. Pure water (H
2
O) is neutral.
6.
How do you test an unknown liquid to see if it is acidic or basic? (Remember that
I will be asking you to perform this task on three unknown (to you) liquids during the test.)
Use acid/base indicators to test an unknown liquid. i.
Start with an acid indicator – for example: bromothymol blue
If Bromothymol blue turns yellow, then the liquid is an ACID. If it stays blue, then it is either a base or neutral. Go to the next step. ii.
Use a base indicator second – for example: phenolphthalein
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If Phenolphthalein turns pink, then the liquid is a BASE. If it stays colorless, then the liquid is NEUTRAL.
7.
What is a neutralization reaction? A neutralization reaction occurs when equal amounts of an acid are mixed with equal amounts of a base. The products are always water and a type of salt.
Write a general word equation for a neutralization reaction. What are the reactants and what are the products?
General WORD Equation: acid + base

water + a salt
8.
Write a general chemical equation for a neutralization reaction.
General Chemical Equation: HX + YOH

H
2
O + YX
(you need to be able to recognize a chemical equation of a neutralization reaction.)
9.
What is a reactive chemical? Name a few reactive chemicals that you use in your house. Why are these chemicals used if they are so reactive?
A reactive chemical is one that easily reacts with other substances. Some examples are many household cleaners, toothpaste, paint, leaded gasoline (no longer available in Canada). We use them because they work – they often clean by using a chemical reaction, so you don’t have to scrub so much. Leaded gasoline was easier to use (less expensive too) and paint with lead runs smoothly.
10.
What is a hazardous chemical? How do manufacturers warn you about possible hazardous chemicals in their products? A hazardous chemical is any product that are dangerous in some way to either you or the environment. They are supposed to be disposed of in very specific ways so that you don’t unintentionally contaminate yourself, the water system or the rest of the environment.
11.
List some common substances that are hazardous chemicals.
Many of the hazardous chemicals that we have in our homes are the reactive chemicals that we listed above. Many cleaners, glues, preservatives, antiseptics, paints and fuels.
12.
What does each of the following hazardous chemical symbols mean?
Corrosive Flammable Explosive Poisonous
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