Year 12s: what will be the first way you research your future options? >>

AS Chemistry- helping each other out!

Scroll to see replies

Hello, could anyone help me out solving a problem. Cannot get the concept of how to solve it.
How many grams of 25% solution you have to pour into 5kg, 30% solution to get 27% solution.
Thank you :smile:

Reply 661

Clovers

Original post by Dylann

Ok so because there are two H+ ions per H2SO4 molecule all you do is double the concentration of H2SO4. Then, figure out which value is smaller, the moles of H+ (2xh2so4 moles) or NaOH. This will be your moles reacted, and you should be able to do the rest :biggrin:

quote if you have anymore problems :biggrin:

Oh, right Thanks :biggrin:

I finally get it now ... Yayy

Reply 662

Feraligatr

Original post by BBeyond

Didn't know there was a copper award? I thought it was just bronze silver gold :tongue:

I didn't do it today, my Chemistry teacher prolonged it to Thursday :colondollar:

Nope, its Copper, Silver and Gold based on the elements in that group :lol:

Reply 663

Alan10

I had an exam where it asked why magnesium hydroxide couldn't be used instead of calcium hydroxide [lime water] for a CO2 test. I put because magnesium carbonate is very soluble so wouldn't precipitate out to make the solution cloudy but just dissolve, whereas others said it was because magnesium hydroxide is insoluble. Which answer seems right?

Reply 664

GingerGnu

Original post by Hayley Williams

Start revising little by little now so the knowledge become second nature! You can't wing chemistry, just a word of warning lol I've seen lots of people try and it doesn't work :smile:

hope all goes well

Posted from TSR Mobile

Thanks for the reply!! I've been trying to go over all the stuff we've covered as I understand most of it but don't phrase it in the right way at times so I've been trying to express ways in which the mark scheme wants :P And I had no plans of winging chemistry - going for that A! Thanks again!

Reply 665

Jessycar10

Hi, i'm doing AQA chemistry :smile:

Reply 666

Jessycar10

Original post by haemo

Same

Are you doing AS or A2? :smile:

Reply 667

Jessycar10

Original post by haemo

AS, you?

AS as well :smile:

Reply 668

SubwayLover1

any tips for the titration practicals??

Reply 669

Loyota

Original post by SubwayLover1

any tips for the titration practicals??

Make sure to take the funnel out of the top of the burette, ensure you wash out your conical flask with distilled water after each titration, measure using your piper very carefully, record to 2 dp, with the 2nd number being a 0 or a 5!

(edited 9 years ago)

Reply 670

SubwayLover1

Original post by Nidfeo

Thanks!!!

Reply 671

Carpe Diem Jay

Also chemistry jokes.

Reply 672

Hayley Williams

Original post by haemo

Energetics is such a lovely topic :biggrin:

I love that too, especially equilibrium! :wink:

Posted from TSR Mobile

Reply 673

danconway

Original post by Jalal Uddin

Also chemistry jokes.

Sodium hypobromite :smile:

Posted from TSR Mobile

Reply 674

TheonlyMrsHolmes

If anybody is struggling with the energetics topic, check out Sara Sephton on youtube. She also has a very detailed video on Group 7, so also check that out if you can! :smile:

Reply 675

Dylann

Original post by SubwayLover1

any tips for the titration practicals??

Read off the miniscus (the bottom of the curve). Also go dropwise when you're about 4cm3 away.

Estimate the finish point of your subsequent titrations and try hard to get concordant results!

Posted from TSR Mobile

(edited 9 years ago)

Reply 676

Dylann

Original post by zhang-liao

I didn't do it today, my Chemistry teacher prolonged it to Thursday :colondollar:

Nope, its Copper, Silver and Gold based on the elements in that group :lol:

Nope it's definitely Bronze Silver Gold. It's the standard three levels of achievement (used in Olympics, hence Olympiad too). You're right that Copper is in the same group, but Copper (with Tin) is a constituent of Bronze.

You're possibly getting confused with the C3L6 challenge, where Copper and Roentgenium are used as they lie in the same group as Silver and Gold! (Rg is the highest award, there's also Entry before Cu)

Additionally, I remember you saying you were due to sit the Olympiad today, how was it? Must have been exceptionally difficult for an AS student, so I hope you didn't give up!

Posted from TSR Mobile

Reply 677

TheMDog

Original post by haemo

Have you started it?

nope
have you?

Reply 678

abz_r786

I've got a chemistry coursework coming up based on observations. I have already carried the practical out - reaction of halogens. I've got the follow up paper that gies with it next and wanted some help on the type of questions that may come up :smile:

Posted from TSR Mobile