Random Definitions

• What is an isotope?

  atoms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei. They therefore have different masses
• what kind of ions do metals always form?

  positive ions
• what is refinery gas used for?

  bottled gas
• what is gasoline used for?

  cars
• what is kerosene used for ?

  airplanes
• what is diesel used for?

  cars
• what is fuel oil used for?

  ships
• what is bitumen used for?

  roads
• Catalytic cracking involves heating the hydrocarbon molecules to around 600 – 700°C to vaporise them
• What is the test for alkenes?

  bromine water + alkene solution -> turns orange bromine water colourless
• Magnesium burns with a bright white flame. Forms a white powder of magnesium oxide. Magnesium oxide is alkaline when it's dissolved in water.
• Hydrogen burns easily and produces a squeaky pop. Burning hydrogen forms water vapour (which has a neutral pH).
• Sulfur Burns with a pale blue flame. Produces sulfur dioxide. Sulfur dioxide is acidic when dissolved in water.
• metal + acid --> salt + hydrogen
• metal + water --> metal hydroxide + hydrogen
• Litmus is red in acidic solutions and blue in alkaline solutions
• Phenolphthalein is colourless in acidic solutions and pink in alkaline solutions
• Methyl orange in red in acidic solutions and yellow in alkaline solutions 
• Litmus paper colour change:

  Acid: red

  Alkali: blue
• Phenolphthalein colour change:

  Acid: colourless

  Alkali: pink
• The common impurity in fuels is sulfur. this burns to make sulfur dioxide. this caused acid rain