Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
13 Cards in this Set
- Front
- Back
|
Name the four main gases present in the air and their % values
|
Nitrogen-78%
Oxygen-21% Argon-0.1% Carbon Dioxide-0.04% |
|
|
Describe how to determine the % of oxygen in the air
|
100cm cubed of air
Pass over heated copper Ensure no air gets in or out Continue until volume of air no longer decreases Should be 79cm cubed |
|
|
Describe lab prep of oxygen
|
Hydrogen peroxide -H2O2 decomposes to form oxygen and water
2H2O2 -> 2H2O + O2 Manganese (iv) oxide is a catalyst Oxygen is slightly soluble in water because it rises to the top of the apparatus |
|
|
Describe the test for oxygen
|
Relights a glowing splint
|
|
|
What happens when you react oxygen and magnesium? Inc. acid/alkali and equation.
|
Bright white flame, white ash left
Alkali 2Mg +O2 -> 2MgO |
|
|
What happens when you react oxygen and carbon? Inc. acid/alkali and equation.
|
Sparks fly
Acid C + O2 -> CO2 |
|
|
What happens when you react oxygen and sulphur? Inc. acid/alkali and equation.
|
Blue flame
Acid S + O2 -> SO2 |
|
|
What colour does blue litmus paper turn when CO2 and SO2 are dissolved in water and why?
|
Blue litmus paper -> red because they are acidic
|
|
|
Describe how to make CO2
|
React calcium carbonate chips with HCl acid in conical flask
Place delivery tube in rubber bung and connect to inverted test tube in water bath Dont discard water when finished Stopper CO2 filled test tube Invert and remove gas with teat pipette Place in beaker filled with limewater - will go cloudy |
|
|
When making CO2, why do you invert the test tube to remove the CO2?
|
It is more dense than air
|
|
|
When making CO2, what colour will the water bath go when UI is added?
|
Yellow (acidic)
|
|
|
Why is CO2 used to carbonate drinks?
|
It is slightly soluble in water and therefore remains as bubbles in the drink.
|
|
|
Why use CO2 in fire extinguishers?
|
It is denser than air and therefore cuts of O2 supplies in fire
|
