A.J's Chemistry

CHEM CONSULTATION

2009-05-13T05:53:00.000-07:00

Few days ago had chem consultation which was helpful..ALOT! i manage to clear my doubts and ask dying chem question plus i also have a chance to teach some of me classmates on why aluminium chloride is covalent bond while aluminuim fluoride is ionic bond..LOL! So i manage to learn quite a chunk and during chem SPA we did some discussions regarding the lemon juice experiment.Which will be conducted next week.GO LEMONS!

More on chem bond..

2009-05-07T08:09:00.001-07:00

Today got back my atomic structure test..Gah! well,i can say that i failed again..this was due to carelessness and lack of understanding for I.E *sigh* WHY MUST I ALWAYS FAIL CHEM!! OF ALL MY H2 SUBJECTS! grrr...i am kinda unhappy about this..SO UNHAPPY..i guess i really have to work harder in order to catch up and well hopefully do well for promos..

Well, learned new stuff in chem bonding.Van der waals attractions,Permanent dipole-dipole attractions and hydrogen bond.

For Van der waals forces,it is an induced dipole0dipole attraction,non-polar molecules and molecules are induced at different time.Therefore,it has different electrons distributions and are very weak.

For permanent dipole-dipole and hydrogen bond still have to read up xD hehe...

And there is like chem hmwk to do!!! TTYL =)

Atomic Structure test& Redox Titration

2009-04-29T04:34:00.000-07:00

Yeah,had chem test yesterday.Really hope i could pass this one..(well,since ive been failing countless of times due to MOLE! Grrr...) But maybe i did one or two screw ups...hope it wasnt that bad.Oh,ill just pray for the better ya *prays >.<*

Had SPA last period.Did redox titration which we use potassium manganate (vi) (izzit? oO) Well,cant remmber wad number..had a hard time doing,and we had insufficient time to complete mayb the 2nd trial and also not forgetting VA5! Gah...which we had to do like overnight and hand in the next morning (was struggling there,ok not really xP) and not to mention my skirt got the potassium stain =.= *sigh* and my mum had a hard time removing it,but at the end the stain is still there..LOL.Well,guess it shall be my remembrance of the redox titration ya xD

Anyhow,tomorrow will be having chem lesson so,ill update on the class then..x3

Redox Reactions

2009-04-25T08:15:00.000-07:00

What ive learnt would be how to identify the oxidation states.I used to be really bad at this or maybe i just forgot how to find it,heh.But i manage to get a gist about the topic.Hopefully,i will be able to catch it too.Ive learnt how to calculate the oxidation number with certain steps to guide me.

The downside,ive been failing my chem test =.= (i bet Mrs Pua is soo gonna kill me *sigh*) Well,IM REALLY BAD AT MOLE! Like since the secondary school..and ive been bragging about this from the star of chem lesson,when our first topic is...MOLE! argh! But,i shall not loose hope..im trying to practise more mole questions,but it seemed a lilttle hard considereing all my other subjects and also catching up on certain topics which i am unfamiliar of..Oh well,i shall do the best of my ability! GO ME GO!

Chemical Bonding

2009-04-24T17:36:00.000-07:00

Ive learnt a new topic which is chemical bonding. There are 3 types of bond, metallic bonding,ionic bonding and covalent bonding.

Metallic bond is the force of attraction between the positive metal ions and the negative delocalised electrons.Also the bond is non-directional and it is strong too.Metals have high degree of electrical conductivity,high thermal conductivity,high melthing and boiling point,shiny,insoluble in water,malleable also can form alloys with other elements.

Ionic bonds are formed when electrons are trasferred from the balence shell of atoms of one element to other atoms.It is an electrostatic attraction between the positive ions (cations) and negative (anions).Its between a metal and non-metal.Is is non-directional and strong.

Covalent bond is the electrostatic force of attraction between the nuclei of each atom for the shared pair of electrons.There is the sigma and pi bond.

Also from these bonds,ive learnt that the way to draw out the electrons for the 'dot and cross' diagram,is slightly different from secondary school.This is also something which,we all need to adapt too xD

Chem..

2009-03-24T10:06:00.000-07:00

Today,ive learnt that im sooo not good in mole! I have always been bad at it..and yeah,i failed m,y timed assignments..(hurray =.=) Anyways,teacher did went through and it kinda help..but somehow i cant seemed to do mole on my own *sobs*

Had SPA,on titration and we have assignment to do which need to be handed like tomorrow morning..woah,but still,ill meet up with a couple of my friends to help me out abit xD Thats about it,which i can remember...Oh ya,and im learning Atomic Structure too (self-study)

Lab Work:Titration Experiment

2009-03-13T22:57:00.000-07:00

Few days ago,my class 09S4 did titration in chem lab.I missed the 1st experiment,so ill share what ive learnt during my attempt for the 2nd experiment.

Ive learnt that before we start on any experiment,we have to plan first.And to take note of the mole ratio and concentration of the solution we are using as a reagent or reactant.Because one mistake i made or shall i say most of us made.Was that our solution in the biurette was needed more than what we expected and it over shot the first reading.From there on,we realise our mistakes and also Mrs Pua explain to us the precautions needed to take.I enjoyed the titration experiment though i was slightly pissed due to my many failed attempts,haha! But at the end i DID get the Results! Yay me =D

Empirical and Molecular Formulae

2009-03-03T08:09:00.000-08:00

Today,ive learnt how to calculate the empirical formulae..1stly by stating the % by mass,Ar,No. of moles,Mole ratio & x4.Some how,i understood the rest except for the x4.[Why is there a need to x4?] Also,now i know there is a general formula for complete combustion.. Yay! xD

Chemistry 1st Tutorials.

2009-02-25T07:23:00.000-08:00

A new topic ive learnt is Binary Covalent Nomenclature.We can recognize binary covalent compounds from their formulas, which contain symbols for only two, nonmetallic elements.And this is something higher from the basic covalent bond.

There is also Cations and Anions.Cations are positive ions while Anions are negative ions.From Cations,one thing new would be that there is only one common polyatomic ion which is ammonium.

Lastly,there is the chemical bonding which I find it easy for me to grasp.And I dotn have much difficulty in that segment.Yay me x3

Little Boy Race..

2009-02-24T07:41:00.000-08:00

What you admire about the little boy in the race?

Ans:I admire his determination in completing the race after a few failed attemps.And his faith in his dad whom believe's in him till the very end of the race.

What is the morale of the story?

Ans:The morale of the story for me would be,never give up or lost hope.Also persevere till the end and stand up after every fall made.And always know that someone,will always belive that YOU CAN DO IT!