Acids and Alkalis Flashcards
What colours do acids and alkalis turn red litmus paper?
Alkalis———> blue
Acid————> red
Neutral——> red
What colours do acids and alkalis turn blue litmus paper?
Alkalis———> blue
Acid————> red
Neutral——> blue
Why do bee and wasp stings cause pain?
Bee and wasp stings cause pain because they introduce venom into your body, tightening the blood cells. Bee stings are acidic and wasp stings are alkali.
How can you reduce pain from bee and wasp stings?
-You can reduce pain for wasp and bee stings by making the area cold.
-You can reduce pain for wasp stings by neutralising it by putting vinegar on it.
-You can reduce pain for bee stings by neutralising it by putting baking soda on it.
What is the pH of a bee sting?
A bee sting has a pH of 3 (same as vinegar).
What is the pH of a wasp sting?
A wasp sting has a pH of 9 (same as bicarbonate of soda).
What is a base?
A substance with a pH greater than 7 that can neutralise an acid. Bases include sodium hydroxide, calcium oxide and copper oxide.
What is the name for the chemical reaction that happens between an acid and an alkaline to make a neutral solution?
Neutralisation.
What is the independent variable?
The variable that you change or select the values for.
What is the dependent variable?
The variable measured for each change of the independent variable.
What is the control variable?
It is the variable that in addition to the independent variable, affects the outcome of the investigation and therefore must be kept constant. We might have more than 1 control variable.
What is a displacement reaction?
A reaction where a more reactive metal takes the place of a less reactive metal in a compound.
For example:
Magnesium + Copper Sulfate —> Copper + Magnesium Sulfate (magnesium is more reactive so will displace copper).
What is a salt?
A compound formed when some or all of the hydrogen from an acid is replaced by a metal.
What gives the salts its first name?
The metal gives the salt its first name. Eg: copper oxide + hydrochloric acid = copper chloride (so copper would be the first name).
What gives the salts its second name?
The acid gives the salt it’s second name. Eg: sodium hydroxide + sulfuric acid = sodium sulfate (so sulfate would be the second name).
Copper Sulfate + Water =…
Copper Oxide + Sulfuric Acid
How do you detect if something is a metal or not?
If something is a metal, it is:
- Good conductor of heat and electricity
- Ductile
- Lustrous appearance
- High tensile strength
- Sonorous
- Hard
How do you test for hydrogen?
You will hear a squeaky pop when a burning splint is held over the open end of a test tube containing hydrogen.
Magnesium Sulfate + Hydrogen =…
Magnesium and Sulfuric Acid
Acid + Base —>…
Salt + Water
Acid + Metal —>…
Salt + Hydrogen
Acid + Metal Carbonate —>…
Salt + Carbon Dioxide + Water
