Turn on thread page Beta

A few basic Chemistry Qs (Mod 1+2)..HELP! watch

    • Thread Starter
    Offline

    0
    ReputationRep:
    If anyone could please please help me, I'd really appreciate it! Got my exam on thursday

    True or false?
    1. Increase in pressure of a gas, increases concentration?
    2. Le Chatelier principle affects yield produced, nothing to do rate?

    3. What is the colour of aqeous chlorine? (green?) Aqeous fluorine?

    4. Does AgF form? (When AgNO3 is added) or does it just stay as NaF for example? Would that be why it is colourless or no change in colour occurs when AgNO3 is added? If AgF does exist, is it soluble in NH3?

    5. Why, in group 7, when more electrons down the group, why does this increase the boiling point?

    6. Which molecules are diatomic?

    Thank you!!
    Offline

    0
    ReputationRep:
    (Original post by Sugaray)
    If anyone could please please help me, I'd really appreciate it! Got my exam on thursday

    True or false?
    1. Increase in pressure of a gas, increases concentration?
    2. Le Chatelier principle affects yield produced, nothing to do rate?

    3. What is the colour of aqeous chlorine? (green?) Aqeous fluorine?

    4. Does AgF form? (When AgNO3 is added) or does it just stay as NaF for example? Would that be why it is colourless or no change in colour occurs when AgNO3 is added? If AgF does exist, is it soluble in NH3?

    5. Why, in group 7, when more electrons down the group, why does this increase the boiling point?

    6. Which molecules are diatomic?

    Thank you!!
    1. False
    2. False
    3. Green, and the other one I don't think you need to know
    4. Prediction: soluble
    5. Greater VDW's forces = stronger bonds between molecules
    6. A lot
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by Whywhywhy)
    1. False - why?
    2. False - why?
    5. Greater VDW's forces = stronger bonds between molecules - why does more electrons = more VDWs?
    6. A lot - is there any way to tell how?

    Thanks
    Offline

    15
    ReputationRep:
    More electrons are being added, and these have to be accomodated in more principle energy levels, which are further from the nucleus, meaning that the atom is bigger - bigger VDW forces
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by imasillynarb)
    More electrons are being added, and these have to be accomodated in more principle energy levels, which are further from the nucleus, meaning that the atom is bigger - bigger VDW forces
    Ok thanks Any idea why these are wrong?
    1. Increase in pressure of a gas, increases concentration?
    2. Le Chatelier principle affects yield produced, nothing to do rate? - when equilibrium shifts it doesn't have any say on rate of the reaction does it? Thanks
    Offline

    0
    ReputationRep:
    (Original post by imasillynarb)
    More electrons are being added, and these have to be accomodated in more principle energy levels, which are further from the nucleus, meaning that the atom is bigger - bigger VDW forces
    not necessarily... it's the increase in number of electrons which increases the chance of temporary dipoles per unit time, hence VDW forces increases.
    Offline

    0
    ReputationRep:
    (Original post by Sugaray)
    Ok thanks Any idea why these are wrong?
    1. Increase in pressure of a gas, increases concentration?
    2. Le Chatelier principle affects yield produced, nothing to do rate? - when equilibrium shifts it doesn't have any say on rate of the reaction does it? Thanks
    actually i think 1. is right. pressure is caused by collisions on the surfaces and between molecules.. so increasin pressure means unit per volume is greater so concentration is lerger
    Offline

    0
    ReputationRep:
    1. Yes

    2. On reaching equiblirum if the system is altered the postion of equilbrium will move to appose the change.

    3. Green, Yellow

    4. A cream precipitate would be formed.

    5. Beacuse the atomic radi of the elemnts is increasing due to a greater nucleaur charge.

    6. The halogens (group7)

    6. Oxygen, Fluorine, Clorne, Iodine

    Thank you!![/QUOTE]
    Offline

    2
    ReputationRep:
    (Original post by Sugaray)
    If anyone could please please help me, I'd really appreciate it! Got my exam on thursday

    True or false?
    1. Increase in pressure of a gas, increases concentration?

    2. Le Chatelier principle affects yield produced, nothing to do rate?

    3. What is the colour of aqeous chlorine? (green?) Aqeous fluorine?

    4. Does AgF form? (When AgNO3 is added) or does it just stay as NaF for example? Would that be why it is colourless or no change in colour occurs when AgNO3 is added? If AgF does exist, is it soluble in NH3?

    5. Why, in group 7, when more electrons down the group, why does this increase the boiling point?

    6. Which molecules are diatomic?

    Thank you!!
    1. The effect of increasing the pressure of a gas is the same as increasing the concentration of a solution

    2. If a factor which affects the position of equilibrium is altered, the equilibrium changes and shifts in the direction which tends to reduce (and oppose) the change.

    Remember that catalyts work on both the forward and reverse reactions, they have no effect on the position of equilibrium but they can increase or reduce the rate at which equilibrium is reached.

    3. yellow (i am not 100% sure on this)

    4. See attachment

    5. more VDW forces => higher bp

    6. the halogens
    Attached Images
     
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by supreme)
    1. The effect of increasing the pressure of a gas is the same as increasing the concentration of a solution

    2. If a factor which affects the position of equilibrium is altered, the equilibrium changes and shifts in the direction which tends to reduce (and oppose) the change.

    Remember that catalyts work on both the forward and reverse reactions, they have no effect on the position of equilibrium but they can increase or reduce the rate at which equilibrium is reached.

    3. yellow (i am not 100% sure on this)

    4. See attachment

    5. more VDW forces => higher bp

    6. the halogens
    Thanks for that scan! And thanks everyone for all the help!
    Offline

    15
    ReputationRep:
    (Original post by supreme)
    1. The effect of increasing the pressure of a gas is the same as increasing the concentration of a solution

    2. If a factor which affects the position of equilibrium is altered, the equilibrium changes and shifts in the direction which tends to reduce (and oppose) the change.

    Remember that catalyts work on both the forward and reverse reactions, they have no effect on the position of equilibrium but they can increase or reduce the rate at which equilibrium is reached.

    3. yellow (i am not 100% sure on this)

    4. See attachment

    5. more VDW forces => higher bp

    6. the halogens
    Seems youve got the same revision guide as me
    Offline

    0
    ReputationRep:
    (Original post by Sugaray)
    If anyone could please please help me, I'd really appreciate it! Got my exam on thursday

    True or false?
    1. Increase in pressure of a gas, increases concentration?
    2. Le Chatelier principle affects yield produced, nothing to do rate?

    3. What is the colour of aqeous chlorine? (green?) Aqeous fluorine?

    4. Does AgF form? (When AgNO3 is added) or does it just stay as NaF for example? Would that be why it is colourless or no change in colour occurs when AgNO3 is added? If AgF does exist, is it soluble in NH3?

    5. Why, in group 7, when more electrons down the group, why does this increase the boiling point?

    6. Which molecules are diatomic?

    Thank you!!
    1.True Concentration is used for liquids .. Pressure used for gases
    2.True if a change occur in a system of equilibrium .. Microscopic process takes place to oppose this change[ didnt mention rate ]
    3.aqeous flourine i assume pale yellow
    5.Well becuz there is an increase in polarisability .. i.e its easier for the electron cloud to be distorted to form a dipole .. so the Vand der waal forces are stronger
    6.Non-metallic elements of group 7 - 6 - 5
    Offline

    0
    ReputationRep:
    I see your questions have already been answered, but I always found this useful:
    Offline

    0
    ReputationRep:
    (Original post by calumc)
    I see your questions have already been answered, but I always found this useful:
    LoooL .. Could it be More usefull
    Offline

    2
    ReputationRep:
    (Original post by imasillynarb)
    Seems youve got the same revision guide as me
    Lol but it is scary as I can see the pages in my mind. :eek:
    Offline

    2
    ReputationRep:
    (Original post by Sugaray)
    Thanks for that scan! And thanks everyone for all the help!
    np
    Offline

    1
    ReputationRep:
    (Original post by supreme)
    Lol but it is scary as I can see the pages in my mind. :eek:
    Lol, I do that in the exam - I start picturing the page of stuff I have to remember and I can actually see the sentences right there... wierd, but I spose it happens after staring at a page for hours on end!
    Offline

    0
    ReputationRep:
    (Original post by FidoDiDo)
    LoooL .. Could it be More usefull
    That particular version is slightly less useful than it at first appears.

    I have no idea where I got it from, probably revising for chemistry or something.
 
 
 
Poll
Do you think parents should charge rent?

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.