M1: Properties and Structure of Matter
Identify an example of a pure substance, homogeneous mixture and heterogeneous mixture.
Correct examples
State the Law of Conservation of Matter
Matter cannot be created or destroyed only transformed
Identify the type of chemical reaction shown
2H₂(g) + O₂(g) -> H₂O(l)
Synthesis
Calculate the molar mass of calcium sulfate.
mm = 40.08+32.07+(4x16) = 136.15 g/mol
The more I dry, the more wet I am. What am I?
A towel
Identify the general trends across periods and down groups for metal activity and ionisation energy.
Metal activity decreases across period and increases down group.
Ionisation energy increases across period and decreases down group.
One mole of magnesium chloride has the same number of atoms as one mole of carbon dioxide. TRUE or FALSE?
TRUE
State the definition of collision theory.
For a successful reaction to occur, reactant molecules need to collide with sufficient energy and correct orientation.
Calculate the % composition of each component of the mixture in the data shown:
Mass of sand + beaker = 151.32 g
Mass of salt + evaporating basin = 36.25 g
Mass of beaker = 105.61 g
Mass of evaporating basin = 33.41 g
Mass of sand = 151.32 - 105.61 = 45.71 g
Mass of salt = 36.25 - 33.41 = 2.84 g
%sand = 45.71/(45.71+2.84) = 94.15%
%salt = 2.84/(45.71+2.84) = 5.85%
What lives if you feed it, but dies if you water it?
Fire
Give the electron configuration (spdf notation) of potassium.
[Ar] 4s¹
The empirical formula of a compound is C2H3N. If its molar mass is 246 g/mol, what is the molecular formula?
C12H18N6
In a silver-lead galvanic cell, what species is the oxidising agent?
Ag+ ions
Calculate the mass of sodium chloride (NaCl) required to make up 250.0 mL of a 0.5000 mol/L solution.
C = n/V; n = C x V
n = 0.5 x 0.25 = 0.125 mol
m = n x MM = 0.125 x (12.99 + 35.45)
= 7.305 grams
What can one catch, but is not thrown?
A cold
Draw diagrams of three molecules that show all three intermolecular forces.
Correct diagrams of three molecules.
Could choose CH4, CH3Cl and CH3OH
Name THREE gas laws besides Ideal Gas Law and their equations
Correctly names and gives equations for THREE gas laws
Explain why reactions get progressively slower until reaction is complete in terms of collision theory
Reaction progresses -> concentration of reactants decrease -> decreased no. of collisions -> less successful reactions -> reaction slows down over time
How much sodium nitrate can be formed from 25g of lead nitrate and 15g of sodium iodide?
Pb(NO3)2 +2NaI → 2NaNO3 + PbI2
m(Pb(NO3)2)=25g, m(NaI)=15g
n(Pb(NO3)2)=25/331.21=0.0755 mol
n(NaI)=15/149.89=0.1000 mol
∴NaI is the limiting reagent
n(NaI):n(NaNO3) is 2:2 or 1:1
m=n×MM=0.1000×84.99
=8.5 g (2 s.f.)
I have no life, but I can die. What am I?
A battery/battery operated device
Give TWO similarities and TWO differences between Bohr and Schrodinger's model of the atom in terms of the nature and location of electrons.
SIMILARITIES
- Both models had electrons structured in energy shell levels
- Both models can show how electrons have move between energy shell levels
DIFFERENCES
- Bohr's model shows basic electrons shells orbits, while Schrodinger's models shows electron orbitals subshells (s, p, d, f)
- Bohr's electrons can be found in circular orbits, while Schrodinger's electron positions are probabilistic mapped in specific 3D shapes
Derive the molar volumes at 0°C, 1atm (22.71 L/mol) and 25°C, 1 atm (24.79 L/mol)
Uses PV = nRT to derive both values
Draw a correctly labelled energy profile diagram of an endothermic reaction INCLUDING annotation to the diagram when a catalyst is added.
Correct diagram with ALL aspects labeled: activation energy, energy of reactants+products, enthalpy, catalyst
Gallium oxide reacts with ammonia to form gallium nitride and water.
Calculate the minimum volume of ammonia gas at 1 atm and 950°C required to react 5.0 kg of gallium oxide with correct sig figs.
Ga2O3 + 2NH3 -> 2GaN + 3H2O
m(Ga2O3 )=5.0 kg=5000 g
n = m/MM = 5000/((69.72×2)+(16×3))
= 26.675 mol
Ga2O3:NH3 is 1:2, ∴n(NH3 )=53.350 mol
P = 1 atm =101.3 kPa ,T = 950°C = 1223.15 K
PV=nRT ; V=nRT/P
=(53.350×8.314×1223.15)/101.3
=5355.72 L
=5400 L (2 s.f.)
What occurs once in a minute, twice in a moment, but never in 1000 years?
The letter 'm'