Chemistry - November 2007

2007-11-20 07:50:45 · 4 answers · asked by ang 1

For some time, a company named John Ellis ( www.johnellis.com ) has had a full page advertisement in Popular Science concerning their machine that produces miraculous water. It is much touted by many Dr.'s, and claims to have a hydrogen bond angle of 114 degrees, compared to regular water's 104 degree hydrogen bond angle... I have no expertise in this area, but am anxious to know if Dr.'s are indeed impressed by this machine. What exactly is a "hydrogen bond angle", and how does it concern me ??? I have visited their site, and still do not understand the information. If you could help me understand, I would really appreciate it.

2007-11-20 07:47:34 · 4 answers · asked by mobileminiatures 5

2007-11-20 07:37:00 · 2 answers · asked by drrivo80 1

A digital watch battery draws 0.20 milliamperes of current, which is provided by a mercury battery whose net reaction is:

HgO(s) + Zn(s) --> ZnO(s) + Hg(l)

If a partially used battery contains 0.70 g of each of these four substances, for how many hours will the watch continue to run?

2007-11-20 07:23:12 · 3 answers · asked by Peter 2

Four beakers of a solution all have a pH of 9.75. If a few drops of (1) Thymol blue, (2) Bromphenol blue, (3) Bromthynol blue, and (4) Phenolphthalein were placed in each beaker separately, what would be the four colors observed? (Enter the letters corresponding to the colors in order, e.q. ABCD, BDCA, etc.)

A) red or pink
B) yellow or orange
C) blue
D) purple or violet
E) colorless

2007-11-20 07:22:31 · 1 answers · asked by Peter 2

The pH of an 0.018 M solution of weak acid A is 2.55. The pH of an 0.042 M solution of weak acid B is 3.06. The pH of an 0.089 M solution of weak acid C is 5.10. Identify the three acids from among those listed below. Find Ka values online.

A) HNO2
B) HF
C) HCHO2
D) HC7H5O2
E) HC2H3O2
F) H2S
G) HClO
H) H3BO3
I) HCN
J) None of the above

2007-11-20 07:21:54 · 1 answers · asked by Peter 2

The pH of an 0.041 M solution of weak acid A is 2.37. The pH of an 0.024 M solution of weak acid B is 2.90. The pH of an 0.097 M solution of weak acid C is 5.08.

2007-11-20 07:18:01 · 3 answers · asked by Chem 111 1

I am concerned about something I have recently been told. DO NOT microwave anything plastic or the chemicals from the plastic will be absorbed in your food

2007-11-20 06:58:09 · 4 answers · asked by useless info 1

Enormous numbers of microwave photons are needed to warm macroscopic samples of matter. A portion of soup containing 330. g water is heated in a microwave oven from 30.°C to 90.°C, with radiation of wavelength 1.55 10-2 m. How many photons are absorbed by the water in the soup?

2007-11-20 06:55:19 · 1 answers · asked by Ruby Winter 2

amonium phosphate
iron (II) oxide
carbon monoxide
calcium chloride
potassium nitrate
magnesium hydroxide
aluminum sulfate
copper (II) sulfate
lead (IV) chromate
diphosphorus pentoxide
potassium permanganate
sodium hydrogen carbonate
zinc nitrate
aluminum sulfite

2007-11-20 06:31:00 · 4 answers · asked by J. Dood 4

1. Actual rates are much greater than the collision frequency for ideal gas molecules
2. Exothermic reactions always have a larger activation energy for the reverse reaction than for the forward reaction
3. The half-life for a zero-order process decreases as the reaction proceeds
4. The concentration of a catalyst will never appear in a rate law

2007-11-20 06:04:01 · 4 answers · asked by Anonymous

a) Is this salt-water combination a mixture, solution, suspension, or emulsion?
b) Explain why no more salt will dissolve in the water.
c) What could you do to this same glass of water to get more salt to dissolve?
d) If you put this glass of salt-water into the freezer, what would you expect to happen to it? (sorry, just saying it will freeze is not enough)

2007-11-20 05:58:32 · 2 answers · asked by Kristyn 1

How many grams of Mg(OH)2 will be needed to neutralize 25 mL of stomach acid if stomach acid is 0.10 M HCl?

How man mL of a 0.10 M NaOH solution are needed to neutralize 15 mL of 0.20 M H3PO4 solution?

2007-11-20 05:53:17 · 2 answers · asked by BH 1

2007-11-20 05:42:21 · 1 answers · asked by chemistry boy 1

What is the cathode pH in Co/Co2+(1.00 M)//H1+(x M), H2(1.0 atm)/Pt if E = 0.03 V? Give the pH to 0.01.

2007-11-20 05:29:20 · 1 answers · asked by Anonymous

What is the standard reduction potential of the Y3+/Y redox couple if the cell potential of the following cell at 25 degree C is 1.28 V?

Zn / Zn2+ (0.20 M) // Y3+ (1.2 M) / Y

2007-11-20 05:28:14 · 1 answers · asked by Anonymous

What is the cell potential of the following cell at 25 degree C? Note Pt is a passive electrode.

Pt / H2 (0.67 atm), H1+ (0.032 M) // Hg2+ (0.58 M) / Hg

2007-11-20 05:26:47 · 1 answers · asked by Anonymous

What is the cell potential of the following cell at 25 degree C? Note Au is a passive electrode

Cu / Cu2+ (0.00850 M) // Cr3+ (0.230 M), Cr2O72- (0.0380), H1+ (1.00 M) / Au

2007-11-20 05:25:29 · 1 answers · asked by Anonymous

2007-11-20 05:03:20 · 5 answers · asked by High Voltage 3

a) if left on the filter will the percent yield of the alum be reported too high or too low? Explain
b) if the Al pieces are detected on the filter what steps would be used to remedy the observation? Explain

thank you for any helo

2007-11-20 04:06:22 · 1 answers · asked by Anonymous

Hi guys....i really require ur help. I wanted to make a ferrofluid. But i cud nt get any oleic acid. Can I use CITRIC acid instead of oleic.Also, i heard the ferrofluid will not be as strong as expected to get spikes. Is this true? Can u give me some tips. I have been using this tutorial for the preparation :

http://chemistry.about.com/od/demonstrationsexperiments/ss/liquidmagnet_2.htm

2007-11-20 03:55:43 · 2 answers · asked by Viveque 1

A decomposition reaction separately occurred for 2 samples (a & b) which contained NaHCO3 (solid) (84 g/mol). Both samples weighed the same but one was pure and one was impure. The product of the decomposition of sample a weighed .25 g and the product of sample b weighed .29 g. Assuming all impurities evaporated during heating:

a. determine the grams of NaHCO3 originally in the pure sample

b determine the grams of impurity in the impure sample

c. determine the % of purity

2007-11-20 03:40:14 · 2 answers · asked by Hey D 1

2007-11-20 03:02:03 · 1 answers · asked by lijo 1

I have to write a chemical equation for a reaction in which HCLO3 is a Bronsed-Lowery acid in water and a chemical equation for a reaction in which CLO3- is a Bronsted-Lowery base in water. Can someone help please.

2007-11-20 02:59:18 · 1 answers · asked by Anonymous

Determine how many grams of Na2CO3 (solid) (106 g/ mol) and CO2 (gas) (44g/mol) are produced from the decomposition of 1.67 grams of NaHCO3 (solid) (84 g/ mol).


thanks in advance!!!

2007-11-20 02:55:41 · 2 answers · asked by Hey D 1

Strontium(Sr) and barium (Ba) both are group ii metal and lie below Calcium. As for metal we know that reactivity increases as we go down in the same group but calcium is placed higher in the reactivity series as in http://en.wikipedia.org/wiki/Reactivity_series
WHY

2007-11-20 00:07:56 · 1 answers · asked by Anonymous

In bleaching process. What's the effect? Is it an oxidation-reduction reaction? Pls explain clearly....
Thx a lot!!!

2007-11-19 23:39:28 · 1 answers · asked by Anonymous

and the number of covalent bonds they form?

2007-11-19 23:35:05 · 2 answers · asked by Thanks For The Help.. (^^,) 1

what happens to the size of the balloon? is the rest to the question.

2007-11-19 23:31:21 · 7 answers · asked by alisha d 1

explain

2007-11-19 23:28:17 · 6 answers · asked by Anonymous