C4 Identifying Reactions and Products Flashcards
How do you detect carbon dioxide?
Limewater turns cloudy white when carbon dioxide is bubbled through it
Test for chlorine
Damp blue litmus paper turns red then white
How to safely smell a dangerous gas
Hold the gas container a few centimetres away from you and waft any smell towards you then take a cautious sniff
How to detect hydrogen
Place a lighted splint near the mouth of the container. It should ignite with a squeaky pop
How to detect oxygen
Place a lighted splint near the mouth of the container. The splint should relight
Lithium (Li+) flame test
Red
Sodium (Na+) flame test
Yellow
Potassium (K+) flame test
Lilac
Calcium (Ca2+) flame test
Orange-red
Copper (Cu2+) flame test
Green-blue
Explain what happens in a flame test
When a metal ion is heated, energy is transferred to their electrons which causes them to move into higher electron shells. When they go back down to their normal levels, energy is transferred to surroundings in the form of radiation, which we see as light.
How to carry out a flame test
Can be carried out using a nichrome loop which you can clean several times dipping it in HCl then rinsing with distilled water. When clean, Bunsen burner flame stays same colour when you hold it over the flame.
Dip the clean loop into the test powder or solution
Use the handle to hold the loop over a blue flame
Record the flame colour
Describe the physical appearance of iodine at room temperature.
Dark grey crystalline solid
Charge on a halide ion
1-
How does boiling point change going down group 7?
It increases
