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Chemistry

A Level

Explain the trend in first ionization energy down group 2. (3 marks)

The trend in first ionisation energy down a group: DECREASES due to:- Increase in atomic radius as there are more shells- Increased shielding...

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The Haber process is used to produce ammonia. (Insert equation here) Explain the optimum conditions for this reaction and why these may differ from the conditions used in industry.

N₂ (g)+3H₂ (g) ⇋ 2NH₃ (g) ΔH=-92kJmol^-1 (this is the equation for the above question)
According to Le Chatelier's principle, the position of equilibrium w...

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Calculate the pH of a 0.0131 mol dm^-3 solution of calcium hydroxide at 10 degrees centigrade.

Multiply by 2 because calcium hydroxide = Ca(OH)2 so 2 x [OH-] per molecule.[OH-] = 0.0131 x 2 = 0.0262
Insert [OH-] value into the equilibrium equation along with the value of Kw at 10 degrees centi...

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Explain why adding small amounts of acid or base hardly changes the pH of an acidic buffer solution.

An acidic buffer solution is made up of a weak acid (e.g. ethanoic acid) and a salt containing its conjugate base (e.g. sodium ethanoate). It resists pH change via two mechanisms: The fact that the acid i...

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In terms of bonding, state the order of boiling point of propane, ethanol and ethanal and why.

The molecule with the highest boiling point is ethanol. This is because of the hydrogen bonding that occurs between molecules from the electronegative oxygen atom and electropositive hydrogen atom. The s...

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