Chemistry

• The 1st name of the type of alkali is the first name of the salt and the 1st name of the acid (roughly) is the 2nd name of the salt.
• A base is an insoluble alkali, but an alkali isn't always a base.
• Bases can't be acids.
• Reactivity series: Potassium, Sodium, Lithium, Calcium, Magnesium, Zinc, Iron, Copper, Sliver, Gold.
• The elements in group 1 are called the alkali metals because they are alkalis when added to water (and have a high pH) which forms hydroxides that give alkaline solutions in water.
• The equation for any neutralisation reaction is: H+(aq) + OH-(aq) = H2O(l)
• All acids contain H+ and all alkalis contain OH-
• At pH 7 the concentration of H+ = concentration of OH-
• Metals and non-metals join together to form chemical bonds.
• The atoms react by losing or gaining electrons. When atoms react this way they get the electronic structure of a noble gas (full outer shell).
• If something is unreactive it's inert.
• When drawing equations compounds don't have the numbers at the bottom of the elements.
• Acid + Alkali = salt + water
• Metal oxide + acid = salt + water
• Acid + Ammonia = ammonium salt + water
• Metal + Acid = salt + hydrogen
• The test for hydrogen gas is called the squeaky pop test.
• Hydroxides is a type of metal compounds that are alkalis.
• Oxides are a type of metal compound that are bases.
• On the pH scale H+ concentration (hydrogen ions) increases x10 as you go left and it decreases as you go right from pH7 (so OH- x10).
• Phytomining is a technique to extract specific metals like copper from it's ore by using plants. The plant absorbs metal ions from the soil using the roots and are then burnt reacting with oxygen to produce copper oxide in ash. The ash is then mixed with sulphuric acid and filtered. It then goes through a process called electrolysis. The positive and negative ions then migrate towards the negative or positive electrode to separate them (they migrate to the oppositely charged electrode).
• Bioleaching is another technique used to extract metals from low-grade ores. It uses bacteria to break the bonds between specific metals like copper from their ores.
• Bioleaching is cheap, doesn't have a lot of energy loss and is environmentally friendly, however it has lots of waste, some toxic chemicals produced, has a low efficiency and is slow.
• A leachate is the solution that contains metal compounds when a liquid passes through bacteria.
• The increase in reactivity further down group 1 because the atoms have more electron shells (as they move down the group) so the electron on the outer shell are further away from the nucleus so the electron is lost more easily from the atom.
• An ion is an electrically charged particle, formed when an atom or molecule gains or loses an electron/electrons.
• The negative electrode in electrolysis is called the cathode.
• An electrolyte is a liquid or solution, usually a molten or dissolved ionic compound, that can conduct electricity.
• The positive electrode in electrolysis is called anode.
• An endothermic reaction takes the energy from it's surroundings in order to break bonds.
• An exothermic reaction emits heat (usually) and therefore releases energy to it's surroundings in order to break bonds.
• In an energy profile diagram to find the energy transferred to surroundings you find how much energy the reactants have and how much the products have then find the difference.