Chemistry - February 2007

is by adding dilute nitric acid followed by dilute sulphuric acid. WHY?Any website with pictures?

2007-02-07 05:54:41 · 1 answers · asked by HeiglLee 2

When a substrate that is catalyzed by an enzyme is present in high concentrations, the effect on the rate of a reaction by changeing the substrate concentration can be described using zeroth-order kinetics. If the concentration of a such a substrate is changed from 2.49 × 10−3 M to 4.53 × 10−1 M, by what factor does the rate of the reaction change ?


That is rate (4.53e-1M) = f × rate (2.49e-3M)

what is the vaule of f ?

2007-02-07 05:31:39 · 2 answers · asked by checa1215 2

2HCl + Ca(OH)2 --> H2O + CaCl2

What is the net ionic equation for the reaction part and which are the spectator ions?

2007-02-07 05:26:44 · 2 answers · asked by Anonymous

It is found that the IR spectrum of methanol contains a peak at 2300 cm-1 and it is "going up". WHat is the source of this peak and why is it "going up"?

2007-02-07 05:22:24 · 2 answers · asked by flyboy87 1

2007-02-07 05:18:13 · 3 answers · asked by phillyfan11 1

2007-02-07 05:12:25 · 11 answers · asked by Diddy C 1

2007-02-07 05:00:33 · 17 answers · asked by bumberclarte 1

From the information given, determine whether the substance described is ionic, polar covalent, nonpolar covalent, or metallic.

a - A gas with an irritating odor was found to dissolve in water but the solution did not conduct electricity.


b - A liquid was immiscible with water and was found to be flammable

2007-02-07 04:58:58 · 3 answers · asked by Anonymous

Hi everyone, I am working on my the synthesis of alum. And now I am just not so sure of the fact that if in the process, we don't cut the aluminum sample into small pieces, but rather left it as one large piece; then will this oversight affect the % yield of alum afterwards? My opinion is that it won't affect the % yield of alum at all. And could anyone know about this stuff please help me out! I need an accurate answer! I'm seriously working on this lab. And please also tell me why it won't affect the % yield of alum, of if it does affect, will the % yield of alum be too high or too low? Thank you very much!

2007-02-07 04:52:42 · 3 answers · asked by cowgirl 1

In chem lab we did an experiment where we generated oxygen from hydrogen peroxide using manganese dioxide as the catalyst. We collected the gas in 5 bottles. In my chem lab report, I have to answer this question: "What is different about the composition of the first bottle of gas collected compared to the other four?" I was under the impression that they were all the same, so if someone would kindly explain it would be greatly appreciated.

2007-02-07 04:43:38 · 3 answers · asked by Jess 2

(OK, please do not kid around now.. I'm being serious. The nail was not dirty(!))

I boiled a finger nail in NaOH for a while. It turned a bit more yellow than it was before. Then I added lead ions and the solution turned greyish-black! Why did that happen (chemically speaking)?

2007-02-07 04:38:45 · 4 answers · asked by maj 1

Chlorofluorocarbons (CFC) act as catalysts for the destruction of ozone in the uper atmosphere.
Ultra violet light from the sun breaks carbon-chlorine bonds in CFC's.



CF2Cl2 ---> CF2Cl + Cl



The Cl atom reacts with ozone.



Cl + O3 ---> ClO + O2
ClO + O ---> Cl + O2



The direct reaction is
O3 + O --> 2 O2



Which of the following are true about these reactions ?



a) The direct reaction breaks down O3 at a faster rate than the same reaction where Cl is used as a catalyst

b) While Cl can be used as a catalyst, it will not appear as an intermediate in the resulting two-step mechanism

c) The presence of Cl provides a mechanism with higher Ea's than the direct reaction (in the absence of Cl)

d) DE (reaction energy) is the same whether Cl is present as a catalyst or not

e) When Cl is used as a catalyst it is a homogeneous catalyst

2007-02-07 04:35:00 · 4 answers · asked by sunyrob 1

When enzymes are present in very low concentrations, their effect on the rate of a reaction can be described using first-order kinetics. If the concentration of a catalyzing enzyme is changed from 3.45 × 10−3 M to 5.38 × 10−1 M, by what factor does the rate of the reaction change ?

2007-02-07 04:34:10 · 1 answers · asked by sunyrob 1

What is the normality of a barium hydroxide solution if 33.6 mL require 71.2 mL of 4.72 M hydrochloric acid solution?

2007-02-07 04:17:06 · 4 answers · asked by Anonymous

If so, theoretically, one can drink this liquid, and take a time-released capsule, (say a half an hour or so), get on a plane and blow them selves up. Is this possible, and if so, what two chemicals? And of so again, how could you deactivate this chemical reaction?

2007-02-07 04:10:45 · 4 answers · asked by wiltzandrew 1

2.Fish generally need an O2 concentration in water of at least 4 mg/L for survival. What partial pressure of oxygen above the water (in atmospheres at 0°C) is needed to obtain this concentration? The solubility of O2 in water at 0 °C and 1 atm partial pressure is 2.21 x 10-3 mol/L.

2007-02-07 04:01:22 · 2 answers · asked by ws 3

2007-02-07 03:43:47 · 3 answers · asked by perfect_imperfection 2

2007-02-07 03:06:51 · 2 answers · asked by perfect_imperfection 2

2007-02-07 03:04:54 · 4 answers · asked by Anonymous

what are five ways in which a molecule stores energy?

2007-02-07 02:55:08 · 2 answers · asked by cutie pie! 3

In the presence of melted NaOH and NaNo3, Mn (IV) can be oxidized to Mn (VII), with formation of NO2 negative. Can anyone help with the equation for this reaction

2007-02-07 02:44:59 · 1 answers · asked by Lost...i think 1

2007-02-07 02:44:13 · 1 answers · asked by Anonymous

if both pumice stone and conc sulphuric acid reacrt then does the pumice stone have to be hot

2007-02-07 02:29:36 · 1 answers · asked by Anonymous

does pumice stone which is calcium silicate react with conc sulphuric acid or does it react anyways with each other

2007-02-07 02:15:41 · 1 answers · asked by Anonymous

2007-02-07 02:11:32 · 6 answers · asked by Bucky 1

Im a grade 7 student doing a science fair project. I am using a syringe to press air through a tube. I want to know what happens to its molecules.

2007-02-07 02:11:15 · 5 answers · asked by Kate L 1

2007-02-07 01:42:57 · 7 answers · asked by Miss LaStrange 5

Will aqueous solutions of each of the following salts be acidic, basic, or neutral? (For each statement select A-Acidic, B-Basic, or N-Neutral. Then enter all 8 correct letters, in order: TTFFTTTF, for example.)

A) CaCl2
B) KBr
C) KHCO3
D) NaHS
E) CsI
F) (CH3)2NH2Br
G) KClO4
H) Na2SO4

2007-02-07 01:41:10 · 2 answers · asked by thesekeys 3

2007-02-07 01:34:16 · 3 answers · asked by Lisa 1

One of my mates mentioned "formula" in relation to weed. Anyone know what it means? I thnk it's a UK term.

2007-02-07 01:31:16 · 3 answers · asked by lazer 3