Chemistry - March 2007

2007-03-05 08:16:59 · 1 answers · asked by watford_boy21 1

The table below is an analysis of the water in natural loch in Scotland

colour hazen units:12.5

TDS:65 mg/l, CL:15 mg/l, SO4 :28.2, Na 6.0 mg/l, K:.83 mg/l,Ca:12.03,Mg:1.701 mg/l

what's your comment briefly on:

1-whether the oxygen content of the water would be expected to be higher / lower in winter compared to summer ?

2-whether the oxygen content would be expected to be higher / lower than on seawater at the same temperature

2007-03-05 08:16:02 · 1 answers · asked by mrezazaimi 1

What causes one of these equation to have a postive answer and one to have a negative answer.
Here are the variables.

HF(g) -271, Cl(g) 122, HCl(g) -92, F(g) 79

Here are the equations

1. HF(g) + Cl(g) (-) HCl(g) +F(g) =
Answer -136 mol


2. Cl(g) + HF(g) (-) HCl(g) + F(g) =
Answer +136 mol


the book using says this is because reversing the direction of a reaction alters the sign of the enthalpy change.

I just like to see the actually math and know a laymen's explantion why these to equaitons are different?

Thank to all that answer.

2007-03-05 08:03:51 · 2 answers · asked by richard d 2

In a weather report, the atmospheric pressure is given as 29.4 inches of mercury. What is the corresponding pressure in mm Hg?

2007-03-05 08:02:09 · 3 answers · asked by chelsea_cruz20 1

2007-03-05 07:53:50 · 1 answers · asked by burcin . 1

will give points to a good answer

2007-03-05 07:53:39 · 14 answers · asked by Anonymous

2007-03-05 07:45:52 · 2 answers · asked by Jackie 2

I've looked but I can't find it =/ Help!

2007-03-05 07:44:47 · 2 answers · asked by Jackie 2

A. An antacid medicine reacting with stomach acid.B.an old garden rake that is rustingC. sawdust that is piling up under a table saw C.a cigarette being smoked

2007-03-05 07:36:15 · 6 answers · asked by SAM 1

metal spherea has a charge -2 and sphere b has a charge of -4. if 2 sphere are brought together then seprated the charge on sphere A will be?

2007-03-05 07:35:13 · 3 answers · asked by Anonymous

The two end produdts of this equation are carbon dioxide(co2) and water. What element should you look at first in balancing this equation?A.oqygenB.hydrogen CcarbonD.dioxide

2007-03-05 07:28:04 · 3 answers · asked by SAM 1

Equation:
3Zn (s) + Al2O3 (s) → 3ZnO (s) + 2Al (s)

Information:
deltaH(reation)=630.86 kJ/mol
deltaS(reaction)=11.66 J/K*mol

deltaG(Zn)=0 kJ/mol
deltaG(Al2O3)=-1582.3 kJ/mol
deltaG(ZnO)=-318.3 kJ/mol
deltaG(Al)=0 kJ/mol


**QUESTION:
What is the change in entropy (J/K-mol) for the universe of the above reaction at 25 oC ?


thanks! I've tried this problem three times and cant seem to get the right answer :(

2007-03-05 07:09:46 · 1 answers · asked by geebgeebgeeb 1

nitrate soloutions

2007-03-05 07:04:54 · 2 answers · asked by Alexander J 1

where is the simplest element converted into helium,and how do i get some to make my voice go squeaky and funny

2007-03-05 07:01:43 · 7 answers · asked by fourjayjames 1

eg. distillation or filtration etc...

2007-03-05 06:51:09 · 2 answers · asked by Chocoholic 2

2007-03-05 06:29:34 · 2 answers · asked by anjs 2

2007-03-05 06:10:59 · 1 answers · asked by Pepple D 1

Basically.. The experiment is to see how many drops of sodium hydroxide it takes to neutralize different concentrations of vinegar (ethanoic acid)....

Would it basically be that the the less concentrated the vinegar, the less drops of NaOH are needed to make the solution turn green (with universal indicator)?
And could anyone expand that a bit please?

(I'm in KS3)
Lorna

2007-03-05 06:09:07 · 4 answers · asked by Anonymous

....if the energy/temperature of the molecules determines the state of the matter? I apologise for the naivety of the question.

2007-03-05 06:09:04 · 3 answers · asked by Andrew H 2

2007-03-05 06:04:01 · 12 answers · asked by Pat F 1

Why is it that longer hydrocarbon chains have higher melting and boiling points than shorter chains?

2007-03-05 06:03:53 · 3 answers · asked by The One 1

I know water tastes different once it is boiled. Is it as healthy and safe as filtered bottled water?

2007-03-05 05:49:11 · 7 answers · asked by neet 1

2007-03-05 05:47:16 · 12 answers · asked by Anonymous

I don't know how/where to break open the ring, or which fragments to remove

2007-03-05 05:44:34 · 1 answers · asked by Karen N 1

Does anyone know what this chemical is ? I found out it is the aroma nutrilizer used in Hefty fresh scent kitchen bags.
I never have problem with cleaning chemicals - the more toxic the better, I say.
This stuff makde me sick.Eyes and nose dripping , sneezing and a feeling that this scent was staying with me 24/7.
Is it used in anything else ?
I looked it up but only found info on the hefty garbage bags not the chemical.
Thanks in advance.

2007-03-05 05:38:52 · 2 answers · asked by Cammie 7

I need a process whereby I will be able to separate activated carbon from wood chips, both containing gold. It must be a process whereby I can extract the gold from each product separately without destroying either product by burning it. The wood chips will be leached-out gold and the activated carbon will be illuted extraction. The process must be able to handle large tonnages of the mixed product. Your input into this matter would be greatly appreciated.

2007-03-05 05:38:10 · 1 answers · asked by discovery 1

Can someone give me the basic word and symbol equation for vinegar (ethanoic acid) reacting with sodium hydroxide - I'm in KS3 so I don't want anything too complicated (with things cancelling eachother out etc).
Lorna

2007-03-05 04:50:36 · 9 answers · asked by Anonymous

2007-03-05 04:50:02 · 3 answers · asked by whitepearls 1

2007-03-05 04:50:02 · 2 answers · asked by Kevin 2

HI,
Some one pleaseeee help me out
i gotta show this to my teacher within 8 hours


I need to know the color of the following salts :


BaCl2 Barium Chloride
NiCl2 Nickel Chloride
NH4Cl Ammonium Chloride
CuSO4 Copper Sulphate
Pb(NO3)2 Lead Nitrate
Kbr Potassium Bromide AND
KI Potassium Iodide

Thanks in advance
Even if you have answered for one or two salts
:O)

2007-03-05 04:41:49 · 2 answers · asked by wp1_wp1 1