***2013 LC Chemistry Before/After***

lizardspock

outnumbered wrote: »

do we need to be able to draw that big, long structure of sopa with the polar and non polar parts?

Yep. Looks so sciency when you draw it out:D

outnumbered

This is what i am/will be studying for the chemistry exam:

No.1 Exp

No.2 Exp

No.3 Exp

Short questions i.e. All defintitions, +whatever will cover me from below. Always manageable anyway.

Fuels and thermochem

Equilibrium/Rates

Acids+bases/Ph and indicator/Water

for the option question: (Radioactivity/Electronegativity/Electrolysis/Gases/Stoichiometry/Oxidation and reduction/Machines)

As a very last resort+an extra question, I will lightly study the important stuff in Q5.

outnumbered

Acciaccatura wrote: »

Alright, I'll try do one today, but I'm warning ye, I can't sing very well :pac:

We're waiting, waiting,waiting, waiting, waiting for something to happen very soon..... #Humms Blissfully

woopah92

Q5 is the easy stuff. I don't get why people don't do it.

outnumbered

woopah92 wrote: »

Q5 is the easy stuff. I don't get why people don't do it.

I usually don't have to. It's the worst answered question in chemistry....
It's do-able but It's not nice in my opinion.

Slow Show

Tommyrawr wrote: »

I think esters will come up in the organic section. They havent had a full Question since 2004 i think.
Well if they do this year thats my favorite section ruined. I just dont understand them at all >.<

When you say a full question do you mean like the soap question? How could they give a full question on just one family?

comeclosa

outnumbered wrote: »

I usually don't have to. It's the worst answered question in chemistry....
It's do-able but It's not nice in my opinion.

I'm with you completely there... Q5 is also like.. the "paragraph answer" question and let's face it who wants to write paragraphs in Chemistry?

Scuid Mhór

well i FOR ONE enjoy writing paragraphs in chemistry!

Slow Show

Yeah I used to think Q5 was a great, dependable q and thought I'd pulled 50/50 in my mocks, only got 35 and I'm still not entirely sure why. If I do it it'll be one out of at least nine!

Hamza Malik

Wanna do a quiz? It might help us with a abit of study? Sooo why do you add sulfuric acid in the titrations?

Prodigious

To provide H+ ions for the reaction.

Define a primary standard.

Hamza Malik

Prodigious wrote: »

To provide H+ ions for the reaction.

Define a primary standard.

I said that answer in the mock and I got no marks.. Primary standard is a substance that can be available in a pure and stable form.

Prodigious

Hamza Malik wrote: »

I said that answer in the mock and I got no marks.. Primary standard is a substance that can be available in a pure and stable form.

Mocks are bull****.

What are the three stresses which LCP applies to?

outnumbered

Hamza Malik wrote: »

I said that answer in the mock and I got no marks.. Primary standard is a substance that can be available in a pure and stable form.

That's because, it's a source of H+ to enusre Mn+7 is fully reduced to Mn+2?

aoifemcg94

Temperature
Pressure
Concentration
adding catalyst

CookieMonster.x

Prodigious wrote: »

Mocks are bull****.

What are the three stresses which LCP applies to?

Temperature, concentration and pressure.

What is the role of Mn+2 in titrations?

Slow Show

CookieMonster.x wrote: »

Temperature, concentration and pressure.

What is the role of Mn+2 in titrations?

It's an autocatalyst - catalyses the reaction.

Give two everyday uses of ethanoic acid.

comeclosa

Hamza Malik wrote: »

Wow I thought I was good at chemistry.. what's lcp ?

LCP = Le Chatelier's Principle
Ethanoic Acid uses= component of vinegar, used to make cellulose acetate, a component in photographic film.

Reagents needed for the sulfite/sulfate test?

Hamza Malik

comeclosa wrote: »

LCP = Le Chatelier's Principle
Ethanoic Acid uses= component of vinegar, used to make cellulose acetate, a component in photographic film.

Reagents needed for the sulfite/sulfate test?

A sulfite salt eg: Baruim cholride and Hcl. What's bod?

outnumbered

Hamza Malik wrote: »

A sulfite salt eg: Baruim cholride and Hcl. What's bod?

It is the levels of dissolved oxygen in a sample of water after being kept in the dark for 20 degrees for 5 days,

what's eutrophication?

Hamza Malik

outnumbered wrote: »

It is the levels of dissolved oxygen in a sample of water after being kept in the dark for 20 degrees for 5 days,

what's eutrophication?

It's the enrichment of the water with minerals causing an algal bloom which use up the O2 in water killing fish life.. sucks to be them :c

What's crystallisation? Eg, water of crystallisation?

outnumbered

It's water that is chemically combined in the formula of a compound?
What's gay-lussacs law?

Hamza Malik

outnumbered wrote: »

It's water that is chemically combined in the formula of a compound?
What's gay-lussacs law?

Gases are in the ratio of small whole numbers under stp.

Avagados law? The one with gases.

woopah92

Hamza Malik wrote: »

Gases are in the ratio of small whole numbers under stp.

Avagados law? The one with gases.

Equal volumes of gases contain equal number of molecules provided they're measured under the same temp. and pressure.

Hess's law?

Prodigious

When a reaction takes place in anumber of stages, the sum of the heat changes of each stage is equal to the heat change if the reaction had been carried out in one stage.

Homologous series?

woopah92

Oh and for gay-lussacs law that def might not get full marks, I'd say:
In a reaction between gases, the volumes of the gases and and any gaseous products formed are in the ratio of small whole number provided they're measured under the same conditions of temp and pressure.

woopah92

Homologous series:
A series of compounds of uniform chemical type, that have the same method of preparation, have a general formula for it's members, show gradations in physical properties and differ from each previous member by a unit. I dunno if that's it fully though

Explain the word amphoteric and give an example of a substance which is amphoteric.

_LilyRose_

woopah92 wrote: »

Homologous series:
A series of compounds of uniform chemical type, that have the same method of preparation, have a general formula for it's members, show gradations in physical properties and differ from each previous member by a unit. I dunno if that's it fully though

Explain the word amphoteric and give an example of a substance which is amphoteric.

A substance which can act as both an acid and a base...eg water is it?

Sequence of colour changes in titrations with starch indicator? (love this question for 12 marks!)

weirdspider

woopah92 wrote: »

Homologous series:
A series of compounds of uniform chemical type, that have the same method of preparation, have a general formula for it's members, show gradations in physical properties and differ from each previous member by a unit. I dunno if that's it fully though

Explain the word amphoteric and give an example of a substance which is amphoteric.

A substance that can act as an acid or a base eg water
State Pauli's Exclusion Principle

outnumbered

woopah92 wrote: »

Homologous series:
A series of compounds of uniform chemical type, that have the same method of preparation, have a general formula for it's members, show gradations in physical properties and differ from each previous member by a unit. I dunno if that's it fully though

Explain the word amphoteric and give an example of a substance which is amphoteric.

It is one which can act as either an Acid or a base depending on the subtance it's placed in. Eg. H2O
Define Electronegativity

weirdspider

_LilyRose_ wrote: »

A substance which can act as both an acid and a base...eg water is it?

Sequence of colour changes in titrations with starch indicator? (love this question for 12 marks!)

red/brown if iodine is used, pale yellow, blue black, colourless
Define atomic orbital

woopah92

Region of space where there is a high probability of finding an electron :pac:

A triad?

outnumbered

weirdspider wrote: »

red/brown if iodine is used, pale yellow, blue black, colourless
Define atomic orbital

I thought it was Dark yellow, then straw yellow .........etc

SecondMan

weirdspider wrote: »

red/brown if iodine is used, pale yellow, blue black, colourless
Define atomic orbital

Region of space where you are most likely to find an electron.

What do flocculating agents do in water treatment and what flocculating agents are used?

weirdspider

outnumbered wrote: »

I thought it was Dark yellow, then straw yellow .........etc

Wait, which titration are you referring to? I just chose the iodine thiosulphate one and the colour of the conical flask is red/brown due to the liberated iodine

Hamza Malik

I bet you guys have chemistry books open in front you right now

weirdspider

SecondMan wrote: »

Region of space where you are most likely to find an electron.

What do flocculating agents do in water treatment and what flocculating agents are used?

They cause supsended particles to clump and aluminium sulphate
Who discovered the electron?

weirdspider

Hamza Malik wrote: »

I bet you guys have chemistry books open in front you right now

That would defeat the purpose of a quiz lol

SecondMan

weirdspider wrote: »

They cause supsended particles to clump and aluminium sulphate
Who discovered the electron?

Me

weirdspider

woopah92 wrote: »

Region of space where there is a high probability of finding an electron :pac:

A triad?

A group of 3 elements with similar properties where the weight of the middle element is approximately equal to the average of the other 2

weirdspider

SecondMan wrote: »

Me

Jaysus JJ you've lived a lengthy life!

Hamza Malik

In relation to recrystalisation of benzoic acid..

Why is it important to use the the least amount of hot solvent at crystallisation stage ?

What would you do if crystals formed on the filter paper?

outnumbered

Hamza Malik wrote: »

In relation to recrystalisation of benzoic acid..

Why is it important to use the the least amount of hot solvent at crystallisation stage ?

What would you do if crystals formed on the filter paper?

To maximise the amount precipitating out
Scrape them off?

ladymacbeth

Hoping for the Iron Tablet experiment as question 1 and a lovely Organic Experiment in question 3. If there was a decent question 3, i would have less to do in section 2 - ideally!

Acciaccatura

The definition video is now on its way, I only got time to do 11 though, and I stress what I said earlier about my singing. Stay tuned :P

Slow Show

outnumbered wrote: »

To maximise the amount precipitating out
Scrape them off?

I think a more precise answer would be to ensure the solution is saturated as with too much solvent, the solution would be too dilute for crystals to form.

As for the second question there, err I dunno really, I know you use the Buchner apparatus with the suction pump to minimise the possibility of that happening, as for those that would form I'd just get rid of them and forget they ever happened. :L

woopah92

Acciaccatura wrote: »

The definition video is now on its way, I only got time to do 11 though, and I stress what I said earlier about my singing. Stay tuned :P

What song are the defintions sung to?

Parawhore.xD

Slow Show wrote: »

I think a more precise answer would be to ensure the solution is saturated as with too much solvent, the solution would be too dilute for crystals to form.

As for the second question there, err I dunno really, I know you use the Buchner apparatus with the suction pump to minimise the possibility of that happening, as for those that would form I'd just get rid of them and forget they ever happened. :L

I was told to pour hot water on the filter paper to allow them to redissolve and filter through I think?

Acciaccatura

woopah92 wrote: »

What song are the defintions sung to?

Lots of different ones, everything from Lady Gaga to Mozart :pac: Gimme another 10 minutes and I'll show you :P

Acciaccatura

Here it is! I'm not gonna lie, I am quite embarrassed about this :pac: I'll just leave all my shame with this post :P

NB: Mods should note that I'm not a regular Youtuber looking for attention and subscribers. I'm far too mediocre for that crap :P