Chemistry - March 2007

2007-03-27 05:10:33 · 8 answers · asked by Anonymous

Henderson-Hasselbalch equation= pH = pKa + log10([A–]/[HA])

We use this equation in order to determine what type of buffer solution is needed to render a target pH. Suppose that we have chosen an acid-base pair with a pKa value that is just slightly less than the desired pH value. Which of the following best describes what we have to do to “fine tune” our buffer solution?

1. Adjust the buffer solution so that [A–] = [HA].

2. Increase the [A–].

3. Decrease the [A–].

4. Increase the [HA].

2007-03-27 05:09:17 · 1 answers · asked by rob d 1

Hydrochloric acid(HCl), hydrobromic acid(HBr), and hydroiodic acid(HI) are all considered strong acids. Another hydrogen halide, hydrofluoric acid(HF) is a weak acid. Why is this the case, when HF has the greatest bond polarity of all these hydrogen halides?

Relative polarity: HI < HBr < HCl < HF

2007-03-27 04:46:05 · 3 answers · asked by rob d 1

Air temp 75 degrees F.
Does air temp make a difference?

2007-03-27 04:37:23 · 2 answers · asked by eventhorizon 2

a) H2O2
b) K
c) Fe
d) Cu
e) C

2007-03-27 04:36:08 · 3 answers · asked by Paul C 1

and what does it mean for crystallinity

2007-03-27 04:32:07 · 10 answers · asked by Anonymous

2007-03-27 04:21:17 · 4 answers · asked by nada_1992_m 1

CHOICES: Covalent bond, Ionic Bond, Hydrogen Bond, Polar molecule, nonpolar molecule

1. Molecules with an equal distribution of charge is called ____?
2. Which type of bond is a very weak attraction?
3.The type of bond where one atom loses an electron and another atom gains it, is ___?
4. Which of the following types of bonds is the only one that can form between atoms of the same element?

Please Help!!!!! Thank you, these are really tricking me!

2007-03-27 04:10:25 · 1 answers · asked by Domino 1

We use infrared spectroscopy (IR) if we have a pure substance. If wehave a mixture to be separated, GC/MS or LC/MS (MS = mass spectroscopy) is probably one of the best qualitative tools.

Anyone can kindly explain to me these methods? Hope u can help me.

Or..can u suggest the other way of separation could be done?

2007-03-27 03:46:41 · 2 answers · asked by Anonymous

Are there any good relatively simple sites where I can find this out?

Also any info on solubility curves please.

Thanks!

2007-03-27 03:38:16 · 1 answers · asked by bezzy_mack 2

2007-03-27 03:27:24 · 1 answers · asked by i-sena 1

and how does copper metal act as catalyst in the oxidaton of methanol in air?

2007-03-27 03:22:20 · 6 answers · asked by CaribbeanChica 3

Pls explain the reason

2007-03-27 03:16:14 · 1 answers · asked by crickwiz 2

A 0.3288- sample of a hydrocarbon (a compound of carbon and hydrogen) was burned in air. The sample was completely converted to 1.0562 g of carbon dioxide and 0.5046 g of water. Find the emperical formula of the compound.







Please if you are not gonna help me do not send me any answers.

2007-03-27 02:48:10 · 6 answers · asked by wjean07 1

2007-03-27 02:45:10 · 5 answers · asked by Anonymous

2007-03-27 02:14:59 · 1 answers · asked by mgp_chem88 1

2007-03-27 01:53:11 · 3 answers · asked by stacyr469 1

2007-03-27 01:50:52 · 1 answers · asked by gzacc 2

2007-03-27 01:14:14 · 3 answers · asked by nomansland127 1

for eg :- Which has higher pH value NaOH or NaHCO3? and why?

2007-03-27 00:56:46 · 2 answers · asked by mistress s~ 2

2007-03-27 00:51:15 · 1 answers · asked by Rujuta 1

2007-03-27 00:26:54 · 1 answers · asked by SANJAY G 1

2007-03-26 23:51:22 · 7 answers · asked by Anonymous

observations:
Sample Taken pH paper colour turned to
I Water Blue
II Dilute HCl Red
III Dilute NaoH Blue
IV Dilute Ethanoic Acid Orange
Which one of the above observations is incorrect?

2007-03-26 23:46:22 · 6 answers · asked by "nee" 1

That button "super ionizer" that lights up when I press it but I don't feel any difference in the room temperature... what does it do? Do I waste more energy lighting it up? Should I light it all the time or just for a short time?
Please explain it to me. Thank you!

2007-03-26 23:07:04 · 1 answers · asked by Changed by Lithium 3

sodium bicarbonate
1. floats on the surface of acetic acid.
2.it remains suspended
3.settles down
4.reacts with acetic acid & forms a clear solution. (pick out the correct answer from the given options)

2007-03-26 23:02:04 · 11 answers · asked by "nee" 1

They use Rocks, minerals, quartz crystals, and things like that for healing.

Can somebody please explain what is up with that?

2007-03-26 22:36:42 · 8 answers · asked by Anonymous

1 Hydrogen gas combines with nitrogen to form ammonia.
2 Hydrogen sulfide gas burns in air to give water and sulpher dioxide.
3 Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate.
4 Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.

2007-03-26 22:08:36 · 4 answers · asked by TJ 2

2007-03-26 21:59:11 · 7 answers · asked by Anonymous

2007-03-26 21:47:34 · 0 answers · asked by blubbablub 1