Turn on thread page Beta

Trend in reactivity down group 2 reaction with water watch

    • Thread Starter
    Offline

    0
    ReputationRep:
    Hi, i have a five mark question here with no mark scheme cause my teacher didnt give me one for it the final question is:

    Describe and explain the trend, down the group, in the reactivity of Group 2 elements with water. (5 marks)

    I got one mark for stating that as you go down the group the reactivity with water increases.


    I was wondering if anyone knew what other things to write about.

    Thanks
    Offline

    11
    ReputationRep:
    (Original post by atman7)
    Hi, i have a five mark question here with no mark scheme cause my teacher didnt give me one for it the final question is:

    Describe and explain the trend, down the group, in the reactivity of Group 2 elements with water. (5 marks)

    I got one mark for stating that as you go down the group the reactivity with water increases.

    I was wondering if anyone knew what other things to write about.

    Thanks
    1) Write an eqn for it,
    M + 2H2O -----> M(OH)2 + H2

    It is metal(II) hydroxide, the 2 should be a subscript.

    2) You see effervescence, due to H2 being released. You also see the solution goes cloudy-ish, ie ppt forming, solubility of the hydroxides decreases down the group as the size of cation gets bigger. The metal obviously slowly disappears as most are consumed up in the reaction.

    3) Like you said, down the group, reactivity increases, because the valence electrons are less bound by the nucleus electrostatic potential, ie lower effective nuclear charge; can elaborate more on this.
    Offline

    0
    ReputationRep:
    The lower the element is in group 2 the more reactive it is. This is because of the shielding effect, where the electron shells shield some of the attraction from the nucleus and therefore the force between the protons and electrons decreases. This is also the same for group 1 and 3 as all of them form positive ions - they loose electrons. I am a student in year 10 and am happy to help you.
    • Community Assistant
    • Study Helper
    Offline

    17
    ReputationRep:
    Community Assistant
    Study Helper
    (Original post by qqwertyuiop)
    The lower the element is in group 2 the more reactive it is. This is because of the shielding effect, where the electron shells shield some of the attraction from the nucleus and therefore the force between the protons and electrons decreases. This is also the same for group 1 and 3 as all of them form positive ions - they loose electrons. I am a student in year 10 and am happy to help you.
    loose (adjective) = when something is not tight
    lose (verb) = to not have anymore

    I am an old git and am happy to help you ...
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: October 4, 2016
The home of Results and Clearing

2,946

people online now

1,567,000

students helped last year

University open days

  1. London Metropolitan University
    Undergraduate Open Day Undergraduate
    Sat, 18 Aug '18
  2. Edge Hill University
    All Faculties Undergraduate
    Sat, 18 Aug '18
  3. Bournemouth University
    Clearing Open Day Undergraduate
    Sat, 18 Aug '18
Poll
A-level students - how do you feel about your results?

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