Explain why compounds formed from non-metals normally do not conduct electricity and have a relatively low boiling point?
Ideal Gas Conditions
Under what conditions of temperature and pressure is the behavior of a real gas most like that of an ideal gas? Explain your answer.
Test For Carbon Dioxide
State the chemical reagent you would use to test for the presence of Carbon Dioxide in the laboratory and give its chemical formulae
Speed Of Reaction (Concentration)
Explain in molecular terms how the rate of reaction is affected by changing the concentrations of reactants
Acidic Gas
Why is Sulfur Dioxide described as an acidic gas?
Buffer
What is the pH of a solution containing 0.10 mol/dm3 Citric Acid and 0.30 mol/dm3 Sodium Citrate?
Citric Acid: Ka = 7.4 x 10^-4 mol/dm3
Isotopes
In a sample of 100 atoms of Boron, there are 20 atoms of Boron – 10 and 80 atoms of Boron – 11.
(i) Explain why these two forms of Boron are isotopes?
(ii) Calculate the relative atomic mass of Boron.
(ii) Calculate the relative atomic mass of Boron.
Strong Or Weak Acid?
A 0.010 mol/dm3 aqueous solution of an acid HA has a pH of 2.0. Is HA a strong or a weak acid? Explain your answer.
Enthaply Change
Calculate the ∆Hsolution, ∆Ssolution and ∆Gsolution for the following equilibrium at 298K.
AgCl (s) <-> Ag+ (aq) + Cl- (aq)
AgCl (s): ∆Hf = -127.0 kJ/mol, ∆Sf = +96.1 J/mol
Ag+ (aq): ∆Hf = +105.9 kJ/mol, ∆Sf = +73.9 J/mol
Cl- (aq): ∆Hf = -167.2 kJ/mol, ∆Sf = +56.5 J/mol
Melting Points
Explain, in terms of their structure and bonding, why the melting points of Calcium Fluoride (CaF2 1418°C) and Phosphorus Trifluoride (PF3 -151°C) are so different?