FINAL Y10AT1

• soluble - can dissolve in the solvent
• insoluble - cannot dissolve in the solvent
• solute - substance which can dissolve
• solvent - liquid in which substance can dissolve
• solution - mixture of solvent and solute
• suspension - mixture of insoluble substance and solvent
• a precipitation reaction is any reaction that produces an insoluble compound when two aqueous solutions are mixed
• sodium chloride + silver nitrate --> sodium nitrate + silver chloride / causing white precipitate
• sodium carbonate + calcium chloride --->sodium chloride + calcium carbonate / slightly white precipitate
• potassium hydroxide + copper sulfate --> potassium sulfate + copper hydroxide / pale blue precipitate
• ammonium - NH4+
• hydroxide OH-
• Sulfate SO42-
• nITRATE no3-
• Carbonate CO32-
• SNAAP rule - sodium , nitrate, acetate, ammonium, potassium
• Law of conservation of mass - the total mass of the products formed in a reaction is equal to the total mass of the reactants
• acid + Carbonate → carbon dioxide + water + salt
• Carbon dioxide passes through limewater, producing a milky solution due to the precipitation of the insoluble suspension of calcium carbonate. The limewater became cloudy. Precipitation is observed. A gas is produced. The universal indicator stays pink.
• 4 pieces of evidence that a reaction is occurring between the hydrochloric acid and calcium carbonate

  • Change in temperature (from 24 to 30)
  • Change in colour (calcium carbonate changed from colourless to milky)
  • Precipitate has formed
  • Production of gas
• Burning fossil fuels can release some pollutants into the air which make rain acidic. Why might acid rain be a problem for society?

  • When acid rain reaches Earth, it flows across the surface in runoff water, enters water systems, and sinks into the soil
• reaction of sodium carbonate + hydrochloric acid --> Carbon dioxide +water + sodium carbonate
• The name of the salt produced comes from the name of the metal in the reaction and the second part of the salt comes from the acid’s name

  E.g. Hydrochloric acid + magnesium carbonate → carbon dioxide + water + magnesium chloride
• Metal (reactive) + acid → salt + hydrogen gas
• reaction of HCI + MG

  • A gas was produced. When Mg added to HCl
  • The gas ignited when exposed to a flame making a “pop” sound
  • The reaction became hot/warm
  • Some possible precipitate formed
  • The Mg decreased in size
• 1. Predict the gas produced by the reaction of and acid and metal. How could you test what gas is produced?

  • Hydrogen gas is produced when the “squeaky pop test was performed a high pitch pop was heard indicating hydrogen gas. If CO2 flame would be put out with no pop, if O2 the flame would have increased with no pop
• Rate of reaction -

  • Chemical reactions involve the breaking and making of chemical bonds
  • For a reaction to occur the reactant particles (atoms, molecules or ions) must collide with enough energy and the correct orientation
  • Rate of reaction - The rate at which reactants disappear or the rate at which products form 
  • Rate of change of concentration with time
• Concentration 

  Increasing the concentration puts more particles in a unit volume. Therefore this increases the chances of collision between particles of one reactant with another reactant breaking and forming bonds (therefore products) much faster. Hence this increases the rate of reaction.

  High concentration:

  • More particles
  • More chance of collision 
  • Faster reaction rate
• Surface area 

  • Breaking big lumps of solid into smaller pieces increases surface area of the solid. The greater the area of one reactant (e.g. solid) exposed to the other reactant. This means that more collisions (hence breaking and forming bonds) can occur in a given time to form products. Therefore this increases the rate of reaction
  • For solid reactant, only the particles on the surface are available for the reaction 
  • If the surface area is increased by breaking up the solid into smaller pieces, more surface is exposed so the reaction rate will increase.
• Effect of surface area

  The rate of a chemical reaction can be raised by increasing the surface area of a solid reactant. This is done by cutting the substance into small pieces, or grinding it into a powder

  Changing the surface area - if a solid reactant is broken into small pieces or ground into a powder:

  • Its surface area increases
  • More particles are exposed to the other reactant
  • There are more collisions
  • The rate of reaction increases
• Temperature 

  As temperature increases, the average kinetic energy (and so the speed) of particles increases. This means that the rate of collisions of one reactant particle with another reactant particle will increase, so the rate of reaction increases.