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An impure sample of sodium carbonate (1.20g) was dissolved in water and the solution made up to 250cm^3 in a volumetric flask. When a 25cm^3 sample of this solution was titrated with Hydrochloric acid (conc. 0.10moldm^-3) a volume of 16.80cm^3 was required for neutralisation. Calculate the percentage purity of the sodium carbonate.

Reaction:

Na2CO3 +2HCl ---> CaCl2 +2H2O

Thanks. If possible could you explain as well as show working, that would really help.

Obviously this is subjective, but I was wondering what each of you thought of all the WiiU games and which were your favourites and your least favoured, and why. Im looking into buying a few more so some suggestions would be great.

I was particularly looking at ZombiU; opinions?

Graçias!

Can decide which 4th game to get for the promotion.

I'm torn between; Casltevania, Monster Hunter 3 Ultimate and Fire Emblem.

Help me chose please? (Reason)

There's a promotion by Nintendo whereby if you purchase Monster Hunter 3 Ultimate on the 3DS, you get a free code for a friend to download it on their system.

I was wondering if there were any people out there who have not got anyone to give their codes to; rather than let this go to waste, it would be greatly appreciated if you were to share with me (or anyone else in the same position).

If you do have one please email me at: jpms@london.com

I'd like to reiterate; I'm not begging here; I'm not trying to exploit or pester people; I'm merely presenting an opportunity where a promotional code does not go to waste, so please do not 'hate' on this or get the wrong idea.

Many Thanks!!!

I am from the UK and am currently 14 years old and a year ahead of my age group doing my GCSE's. I am getting A* and A's in all of my 14 GCSE's that I am doing at the moment and was wandering if it was possible to do the SAT and ACT exams (American) in the UK so that I can apply to an American College. The SAT and ACT being the exams that American students do when they are going to leave to go to college not to be confused with the UK SAT which we did when we were 8 years old.

Many Thanks

I am from the UK I am only 14 but am preparing and thinking about where I want to go to university and am seriously considering an American College. But I was wondering if It would be necessary to do any extra tests for example SAT. Also would I need to calculate a GPA using my GCSE's and/or A-Levels or anything of the sort

Many Thanks

I would like to know how many people apply to Harvard and how many of which get in. I do ask that you don't copy a statistic from 4 years ago as many of these flood the internet and I would imagine that the number has changed since then. And if possible could you tell me what percent of students at Harvard are International.

Many Thanks

I am 14 from London and I want to take up some extracurricular activities. I am very strong academically but want to expand on this and any help would be greatly appreciated.

I already; speak 4 languages, cook, do army training in school (CCF) and Photography.

I am passionate about what I do so that should be no problem (although I do have a medical condition that doesn't allow me to take part in sorts very often)

I would also like you to consider what activities would look good when applying to a university.

When I plug in MY iPad 2 in to either of MY computers it says that in order to sync my music e.t.c... it will wipe the rest of the music I have on there. I don't want to do this as I don't have the files on there anymore. I have tried to authorise both commuters onto my account but it won't work I transferred all my purchases and both computers and the iPad are on the same account. How do u sync without loosing data (WITHOUT JAILBREAKING)

I use photoshop CS5 a lot, i know they are completely different but many people find photoshop hard to use/learn. I also use cinema4D but i am not an expert on it. I have never used xcode before, will it take a long time to learn? (dont think that i mean photoshop is a form of editing, I only mentioned it as a form of comparison)

Okay, a really good friend of mine worked at rockstar and he got let go recently as they couldn't fund his payment. he told me everything he knew about gta5 including the fact that all the trailers have already been made. i want to share this with people as he said i could because he has nothing to lose but i dont know how ?! where to i send it ?

I would like to know what are the main advantages to a better rate of photosynthesis when using science to help us. please give reasoning.

Many Thanks :)

this is for educational purposes so please dont give me a lecture of how it is 'illegal' because i know that already, so answer the question or leave.

and by music i mean charts, rap, RB e.t.c...

I was diagnosed with hepatitis A today and I went to the doctors as i suspected this after a self diagnostics. My symptoms are jaundice, influenza, no appetite, high consentration urine, hyperbilirubinemia and they did a blood test. I am 14 very active have a good diet and much cleverer than an average 14 year old as I speak 4 languages and have 12 A* in my GCSE. I know what hepatitis A is and how you get it but how will it affect me in my day to day life.

I should also mention that I have thalassemia and DO NOT DO DRUGS OR ALCOHOL.

My question is : what are the outcomes of hepatitis A?

I recently sat my science unit 1 exam for AQA, it counts for 25% of my final grade and I got a B in all 3 sciences which I was really upset about.

In chemistry and physics I got 46/60 and I needed 48/60 to get an A

Do you think it is likely for AQA remark it and give me 2 more maks or will it be a waste of time?