ppq notes chem

• label

  A) gain electrons

  B) 4e-

  C) carbon

  D) oxygen

  E) graphite

  F) allotrope

  
• label

  A) gas

  B) bromine

  C) lose

  D) electrons

  E) bromine atoms

  F) oxidised

  G) pairs

  H) bromine molecules

  
• exothermic: a reaction which gives out HEAT energy
• polystyrene cup is better because

  1. it insulates heat better
  2. so reduces heat loss
  3. so temperature readings are more accurate
• low boiling point = weak intermolecular forces so little energy needed to overcome the forces MUST REMEMBER SECOND PART U ALQAAYS FORGET IT
• label

  A) giant tetrahedral lattice

  B) strong

  C) hard

  D) layers

  E) weak forces

  F) slide over

  G) soft

  
• measure mass of spirit burner IMMEDIATELY after heating water to minimise mass lost by evaporation of fuel
• concentrated sulfuric used for esterification as catalyst
• the water jacket in fractional distillation is a condenser
• metal oxide can only react with carbon if metal is less reactive
• alloys are harder than pure metals because pure metals are in a regular arrangement so the atoms slide over each other easily. having different sized particles breaks up the regular arrangement so makes it harder to slide over each other
• when electrolysing h2so4, dont use zinc electrodes bc zinc would react with h2so4
• test for sulfate ions: barium chloride, white precipitate forms (barium sulfate)
• test for carbonate ions: add dilute acid (eg hcl) and bubble through limewater because co2 is produced
• lymphocytes produce antibodies
• rbc have biconcave disc shape, maximised sa:vol so max haemoglobin for more oxygen
• artificial blood doesnt have platelets
• make red blood cells make rbc with blood group o because there are no antigens in o so antibodies will not be produced so wont reject the blood so anyone can receive it
• Cathode (preference over H⁺ ions):

  1. Metal ions with a lower standard electrode potential (more positive) than H⁺ ions, such as:

  • Na⁺ (sodium)
  • K⁺ (potassium)
  • Ca²⁺ (calcium)
  • Mg²⁺ (magnesium)
  • Al³⁺ (aluminum)
  • Pb²⁺ (lead)
  • Cu²⁺ (copper)
  • Ag⁺ (silver)
  • Fe²⁺ (iron)
  • Zn²⁺ (zinc)
  • Ni²⁺ (nickel)
  • Sn²⁺ (tin)
  • Hg²⁺ (mercury)

  Anode (preference over OH⁻ ions):

  1. Halide ions (Cl⁻, Br⁻, I⁻) with a lower standard electrode potential (more positive) than OH⁻ ions:

  • Cl⁻ (chloride)
  • Br⁻ (bromide)
  • I⁻ (iodide)
• lBEL

  A) pipette

  B) conical flask

  C) methyl orange

  D) burette

  E) initial

  F) reading

  G) flask

  H) swirling

  I) indicator

  J) final burette reading

  K) volume

  L) repeat

  M) concordant results

  
• ethanol can be oxidised to produce carboxylic acid. give the name of 2 REAGENTS used in this OXIDATION reaction

  • potassium dichromate (turns orange to green)
  • sulfuric acid
• explain why lamp doesnt light up when lead(ii) bromide is solid:

  • ions not free to move to conduct
  • only can conduct when molten
• bromine would be a brown / orange gas at the positive electrode
• explain why a reaction is exothermic

  • energy needed to break bonds (endothermic)
  • energy given out when bonds are formed (exothermic)
  • energy given out is greater than energy needed
• gasoline - cars (land)

  kerosene - plane (sky)

  diesel - lorries (land)

  fuel - ships (sea)
• copper IONS are blue not copper solution
• in titration, rinse the conical flask w water, but the burette with the acid / alkali
• label

  A) water

  B) pipette

  C) not

  D) water

  E) acid

  F) initial

  G) white tile

  H) swirl

  I) drop

  J) end point

  K) repeat

  L) average

  M) concordant

  
• label

  A) 2h2o

  
• label

  A) dissolve

  
• sulfide = s2-

  sulfite = so3 2-

  sulfate = so4 2-
• base + ammonium salt -> salt + ammonia + water
• base + non metal oxide -> salt + water
• whats a compoubnd

  A) 2

  B) elements

  C) bonded

  
• why did the dye not move

  A) soluble

  
• why solid still can conduct?

  A) metal

  B) connects

  C) electrodes

  D) circuit

  
• alkali metal in water

  A) moves

  B) disappears

  C) colourless solution

  D) heat

  
• label

  A) cooler

  B) hotter

  C) condense

  D) collected

  E) boiling point

  
• why metal is malleable

  A) layers

  B) positive ions

  C) slide over

  
• characteristic of dynamic equillibrium

  A) rate

  B) forwards

  C) concentrations

  D) remain constant