Shells Chemistry Flashcards
What two chemicals are used to test for the presence of water and what colour change is seen if water is there?
Anhydrous copper sulphate goes from white to blue Cobalt chloride goes from blue to pink
What is the percentage of oxygen in the air?
21%
What is the percentage of nitrogen in the air?
78%
What is the percentage of carbon dioxide in the air?
0.03%
Approximately 1% of the air is made up of “other gases” what are these gases?
Mainly argon and water vapour
What is the reactivity series for metals? From most to least reactive (include hydrogen and carbon).
Potassium, sodium, (lithium), calcium, magnesium, aluminium, carbon, zinc, iron, tin, lead, hydrogen, copper, silver, gold, platinum.
What is the name given to the type of reaction where a more reactive element pushes a less reactive on from a compound?
Displacement reaction.
What is used to test whether a liquid is acidic or alkali?
Universal indicator paper or litmus paper
What colour does litmus paper go in acid?
red
What colour does litmus paper go in alkali?
Blue
What colour does universal indicator go in weak acid (pH 5-6)?
Yellow
What colour does universal indicator go in medium alkali (pH 10-11)?
Blue
What is the pH of a strong acid?
1 or 2
What is the pH of a strong alkali?
13 -14
Vinegar is a medium acid, what colour would it go in universal indicator?
Orange