Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    • Thread Starter

    Hi ive got a few chem questions im really stuck with if anyone could help?

    i) 2SO2(g)+O2(g) <-> 2SO3(g)
    ii) H2(g)+I2(G)<->2HI(g)

    If the pressure was decreased would the yeild in (i) be greater or less, and for (ii) be greater or less?

    "Which homologous series is isomeric with alcohols?"

    CH3CH2COOH(aq) <-> CH3CH2COO-(aq) + H+(aq)
    "Write the expression for the dissociation constant, Ka"

    Calculate Ka given that a 1.0x10-2 mol dm-3 solution of propanoic acid has a pH of 3.43"

    If anyone can answer any of them that would be great thankyou

    1) do you understand Le Chatelier's principle? Basically, in a reaction involving gases where there is a different number of molecules on the left versus the right, an increase in pressure will favour the direction producing the last number of molecules. Decreasing the pressure will do the opposite.

    2) a homologous series is a series of compunds with the same ratio of atoms, eg alkanes CnH2n+2. Alcohols are series with the general formula CnH2n+1O

    What else follows that pattern?

    3) the dissociation constant is the ratio of the product of the concentrations of the RHS divided by the concentration of the LHS

    Can you do it now?

    4) pH=-\log_{10}[H^+]

    so that allows you to calculate the concentration of H+ from the pH

    the just plug that in to the equation from 3)

How are you feeling about your exams?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.