Chapter 27- The Atmosphere Flashcards Preview

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Flashcards in Chapter 27- The Atmosphere Deck (11)
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1

Experiment to prove:
Oxygen occupies 21% of air (iron)

Upside down graduated cylinder w/ steel wool at the very top
Placed in trough
Iron will react with oxygen sucking water up to 21sm mark on the cyclinder

2

Experiment to prove:
Oxygen is 21% of the atmosphere

One syringe has 100mm^3 of air, one closed

Heat and pass air

Copper turns grey black (now copper oxide)

Air=80cm^3 as oxygen has reacted with the heated copper

3

Experiment to:
Prepare oxygen

•Put hydrogen peroxide in syringe
•Through stopper on beaker with manganese dioxide in it
•They react when released
•Oxygen goes back out stopper, down tube, under beehive shelf and up into a test tube (previously filled with water)

4

Tests for oxygen

1. Colour, smell, pH ----------> colourless, odourless, neutral
2. Glowing split in jar --------> Ré-lights
3. Burn magnesium ribbon---> burns white light

5

Experiment to:
Prepare carbon dioxide

•Hydrochloric acid dropped from syringe, through stopper
• reacts with calcium carbonate
•Co2 goes up, down tube, under beehive shelf, up test tube

6

Word equation for the preparation of oxygen

Hydrogen peroxide +manganese dioxide --->Oxygen +water

2H2O2+MnO2--> O2 + 2H2O

7

Word equation for the preparation of Co2

HCL + CaCo3 = CO2 + H2O+ CaCl2

Hydrochloric acid + calcium carbonate
=
Carbon dioxide + Water + Calcium Chloride

8

3. Tests to prove Co2

1. Colour, smell, pH ----------> colourless, odourless, acidic
2. Add limewater ------------> colour change
3. Pour on candle -----------> extinguishes

9

Equation for limewater and Co2

Calcium hydroxide+Carbon Dioxide->
Calcium Carbonate+Water

Ca(OH)2 + Co2 -> CaCO3 + H2O

10

Uses for Co2

-fire extinguishers
-fizzy drinks
-fridges
-stage effects

11

Nitrogen

78% of air
Unreactive
Condenses at -200°c