Full Chemistry A Bundle.

What is the aim of this practical? To determine the enthalpy change of reaction by Hess' Law based on experimental evidence. This will involve measuring the temperature changes in the reactions of both K₂CO₃ and KHCO₃ with hydrochloric acid and applying your knowledge of Hess' Law to ca...

A student prepares a solution of calcium nitrate by reacting dilute nitric acid, HNO3, with the base calcium hydroxide, Ca(OH)2. (i) Why is calcium nitrate an example of a salt? - Ans .The H+ ion in a nitric acid has been replaced by a metal ion OR by a Ca2+ ion MCl2.2H2O is a salt with water...

1. The melting point of XeF4 is higher than the melting point of PF3 Explain why the melting points of these two compounds are different In your answer you should give the shape of each molecule, explain why each molecule has that shape and how the shape influences the forces that effect the mel...

Explain why the first ionisation energy of barium is less than the first ionisation energy of calcium - Ans .-more (electron) shells / (outer) electrons further from the nucleus / larger atoms / more shielding -so weaker attraction of nucleus/protons for (outer) electrons Magnesium reacts readi...

▪ In the periodic table, element X is in group 2 and element Y is in group 5. what is the likely formula of the ionic compound of X and Y - Ans .X3Y2 ▪ which enthalpy changes are endothermic - Ans .the bond enthalpy of a C-H bond and the second electron affinity of oxygen ▪ explain why t...

alcohol - Ans .add acidified potassium dichromate - orange to green aldehyde - Ans .add Tollen's reagent - silver mirror formed metal fluoride - Ans .add dilute HNO₃ then a few drops of AgNO₃ solution - no ppt formed metal chloride - Ans .add dilute HNO₃ then a few drops of AgNO₃ solu...

Equipment • Measuring cylinder (10 cm³) • Dropping pipettes • Quickfit apparatus: • Pear-shaped or round-bottom flask • Liebig condenser and tubing • 250 cm³ beaker • Glass rod • Anti-bumping granules • Apparatus for filtration under reduced pressure (Buchner funnel and ...

Give an equation for the combustion of heptane (C7H16) in an excess of oxygen - Ans .C7H16 + 11O2 --> 7CO2 + 8H2O Heptane can be obtained from the catalytic cracking of hexadecane (C16H34) at a high temperature. Identify a suitable catalyst for this process.Give one condition other than high ...

1. Iodide ions are oxidised to iodine by hydrogen peroxide in acidic conditions. H2O2(aq) + 2H+(aq) + 2I-(aq) → I2(aq) + 2H2O(l) The rate equation for this reaction can be written as rate = k [H2O2]a [I-]b [H+]c In an experiment to determine the order with respect to H+(aq), a reaction mixture...

Describe what happens when a reaction mixture is refluxed and why it is necessary, in this case, for complete oxidation to ethanoic acid. - Ans .A mixture of liquids is heated to boiling point for a prolonged time; Vapour is formed which escapes from the liquid mixture, is changed back into liqu...

Equipment • Test tubes. • Test tube rack. • Dropping pipette. Part A: • Heptane • Cyclohexane • Cyclohexene • Limonene Part B: • 1-chlorobutane • 1-bromobutane • 1-iodobutane • Ethanol • Aqueous silver nitrate Method - Part 1: Identification of an alkene For t...

Van der Waals' forces exist between all molecules. Explain how these forces arise. - Ans .- Electron movement in first molecule. - Induces a dipole in another molecule - δ+ attracts δ- in adjacent molecules 1) Name the type of bond formed between N and Al in H₃NAlCl₃ and explain how this...

Relative atomic mass - Ans .The average mass of an atom of an element, relative to 1/12th of the mass of an atom of Carbon-12 Relative molecular mass - Ans .Average mass of a molecule compared to 1/12th of the mass of a carbon-12 atom The Avogradro constant - Ans .the number of particles in...

▪ Atomic number - Ans .Number of protons in an element ▪ Mass number - Ans .Number of protons and neutrons ▪ Ion - Ans .Electrically charged particle formed by the loss/gain of electrons ▪ Relative masses of P,N and E - Ans .1,1, 1/2000 (respectively) ▪ Isotopes - Ans .Atoms of the sam...