Chemistry - October 2007

An article todays states that we throw away one third of our grocery shopping and that is impacting on Co2 levels. Does anyone know what the methane output of one third of our food eaten is? Wouldn't it have the same impact or more?

2007-10-31 23:31:52 · 2 answers · asked by Lozzie p 2

It reacts with the alkali metals (M) to form a salt MX, where X is the halogen.
Its hydrogen halide, HX, forms an acidic solution.
It is prepared by electrolysis from a molten salt.
It forms interhalogen compounds only of the form XA, where A is the unknown and X is another halogen.

1. fluorine 2. chlorine 3. bromine 4. iodine

2007-10-31 21:36:05 · 2 answers · asked by dbdwnd 1

I did a redox experiment where I got H2 to be released from water by sending electricity into a metal in water. The metal lost .024 grams and 50 mL of H2(g) was collected.
I established the half reaction was 2e-+H2O->H2, and the problem said, (1 mole e- = 1 faraday)
The following problem says, "With knowledge of EM, the molar mass of your metal (MM) may be calculated using the equation MM = EM x n. Here, n is the charge of oxidaized metal cation, so MM simply represents a multiple of EM. For instac,e for EM=24, MM has possible values of 24 g mol^-1 (for n=+1), 48 gmol^-1 (for n=+2)...etc.

The problem is "The equivilant mass (EM) of a metal is the mass of metal oxidized by 1 f (faraday).In this experiment EM is calculated using the following equations
EM=metal lost(g)/f
This expression assumes that 1f is required to oxidize 1 EM of metal. Using your data, calculate the EM for your metal."

In order for that to happen, EM has to be above 1 but metal lost is .024, so how do I get EM>1?

2007-10-31 21:26:46 · 1 answers · asked by Anonymous

2007-10-31 21:05:10 · 0 answers · asked by Kainon 1

I recently did an experiment for the determination of OCl- in bleach. The acutal value in commerical bleach is 5.25%, but when my group did all of the redox titration calculations, the experiment value turned out to be 4.67%. The experimental error was 9.40%. What do these results mean and how can i talk about them in the discussion part of my lab report?
If anyone can help me, it would be really appreciated. Thanks.

2007-10-31 18:28:50 · 2 answers · asked by Anonymous

54.70 mL of 0.162 M AgNO3
48.30 mL of 0.161 M K2CrO4
Mixing the following solutions resulted in the isolation of 1.37 g of Ag2CrO4

2007-10-31 18:21:40 · 2 answers · asked by Anonymous

2007-10-31 18:06:50 · 1 answers · asked by Sean P 1

Ksp = 1.8e-7

2007-10-31 17:11:32 · 1 answers · asked by Nicole G 2

chemistry
heat and gas laws
mainly
charles and gays

2007-10-31 15:13:44 · 3 answers · asked by saringan 2

I just want to know it's boiling point.
Thank you.

2007-10-31 13:56:38 · 2 answers · asked by deus 2

If solid CH3COOK, potassium acetate, is dissolved in water, will the resulting solution be acidic, basic, or neutral? Why?

2007-10-31 13:53:08 · 1 answers · asked by anners 1

In a mixture of Ne and H2 gases, the partial pressure of Ne is 0.150 atm. The total pressure is 0.405 atm. The temperature is 36.0oC. If the total volume of the gas mixture is 433 mL, what is the mass of H2 in grams?

2007-10-31 13:45:57 · 3 answers · asked by Anonymous

I’m stuck on some problems for a lab report. Here are the questions, and my thinking on them so far:

A) Each of the following samples contains only one of the two chemicals indicated. What reagent would you use to identify which of the chemicals is present that you would use to distinguish between the two chemicals? Explain your choice.

1) Na2SO4 and NaI (Reagent: BaCl3 or FeCl3)

Leaning towards BaCl3, because it produces a precipitate with NaI only.

2) Fe(NO3)3 and Zn(NO3)2 (Reagent: NH3 or K4[Fe(CN)6])

NH3, because the other introduces Fe whether or not it is already present?

3) K3PO4 and Na2CO3 (Reagent: (NH4)2MoO4 or HCl)

I’m at a loss for this one.

B) How would you go about testing for the presence of SO4 in the presence of NO3?

Add a base first, or something else to react with the NO3 before you add the BaCl2, so that the Ba isn’t all used up in the formation of soluble barium nitrate. Maybe just excess BaCl2?

Tips and/or answers greatly appreciated!

2007-10-31 13:37:09 · 2 answers · asked by Anonymous

What is the wavelength in meters of the photon emitted when this highly excited hydrogen atom of hydrogen makes its transition from the n = 9 to the n = 8 state?

2007-10-31 13:36:29 · 1 answers · asked by Anonymous

The bright-red color of highway safety flares comes from strontium ions in salts such as Sr(NO3)2 and SrCO3. Burning a flare produces strontium ions in excited states, which then emit red photons at 606 nm and several wavelengths between 636 and 688 nm. Calculate the energy (in Joules per mole) of the 684-nm emission.

2007-10-31 13:35:40 · 1 answers · asked by Anonymous

2007-10-31 13:27:01 · 1 answers · asked by John S 1

They are basicly the samething one's just stronger than the other...

2007-10-31 12:46:44 · 2 answers · asked by Anonymous

Calculate the pH of the solution that results from the addition of 0.020 moles of HNO3 to a buffer made by combining
0.500 L of 0.060 M NH4Cl ( use Ka = 5.60 x 10 -10 )
and 0.500 L of 0.120 M.


The question is apparently cut off at the, but I believe you do not have to necessarily know the substance, since NH4Cl is a salt.

pKa=9.25181


Everytime I have done this problem, I have gotten an incorrect answer. Please help. I have been using the Henderson-Hasselbalch equation to solve this.

(-log(5.60 x (10^(-10)))) + log(.01 / .08) = 8.34872199

I don't understand what I'm doing wrong.

I thought that maybe if I switched it up (I don't know why), it would work but that is also wrong.

(-log(5.60 x (10^(-10)))) + log(.08 / .01) = 10.154902

2007-10-31 12:35:03 · 1 answers · asked by Sage 1

what is the difference during a lab?

2007-10-31 12:19:40 · 1 answers · asked by GhostVault 23 2

2007-10-31 12:03:02 · 2 answers · asked by dz 1

well the question goes like this :Calculate the pH of an ammonia solution made by diluting 25.0 mL of 0.204 M NH3 to a total volume of 50.0 mL.
a.) 2.87 b.) 8.26 c.) 9.25 d.) 11.13 e.) 11.78

The way i approach this question is as follows i have the intial mole sand volume so M1V1=M2V2 ...
so 25*.204= 5.1
then 5.1/50= .102
then i take the molar mass of ammonia which is 17 and i divide the .102/17=.006
then i do -log (.006) =2.22
so then i do 14-2.22= 11.78 which is one of the answers if anybody can confirm or deny, any additional help is appreciated

2007-10-31 11:59:24 · 2 answers · asked by Fredrick J 2

science question
please answer it scientifictly

2007-10-31 11:43:20 · 4 answers · asked by blueberry,channel,all my faves! 2

Scandium
Titanium
Vanadium
Chromium
Manganese
Iron
Cobalt
Nickel
Copper
Zinc
These elements are transition metals in groups 3 to 12, so I dont know how much valence electrons they each have.

2007-10-31 11:35:07 · 1 answers · asked by Brandon 1

Unknown compound:
solubility: high
solution color: colorless
flame color: orange
acidity: neutral
conduct electricity?: yes

which compound is it from the following?
barium nitrate
calcium nitrate
potassium nitrate
sodium nitrate

2007-10-31 11:24:28 · 2 answers · asked by Tod T 2

this is a chemsity question

2007-10-31 10:27:50 · 3 answers · asked by skycap756 2

I need some help with these puns. The answers are all elements.

1. A motto for a well digging company
2. Get him
3. Holium x 0.5
4. Chemical apache
5. Directions (past tense)
6. Result of swallowing food coloring
7. a kitchen area with a drain
8. what police do to a bookie joint
9. An amusing prisoner
10. what you do before you brand a steer
11.If your hair falls out you...
12. A large building used to store autos
13. last words of a dying man
14. funds from mother's sister

2007-10-31 09:18:23 · 4 answers · asked by SJohnson 3

Calculate the pH of the solution that results from the addition of 0.020 moles of HNO3 to a buffer made by combining
0.500 L of 0.290 M NH4Cl ( use Ka = 5.60 x 10 -10 )
and 0.500 L of 0.580 M

I get 9.39 and it's wrong.

2007-10-31 08:36:17 · 1 answers · asked by JC 1

Explain why most chemical bonds would be classified as either polar or covalent or ionic.

2007-10-31 08:28:36 · 4 answers · asked by Anonymous

http://upload.wikimedia.org/wikipedia/commons/c/c5/Zitronens%C3%A4ure_-_Citric_acid.svg

is the Whats the O and H for and by the way this is a structure of Citric acid

2007-10-31 08:23:31 · 2 answers · asked by Anonymous

I'm looking for some simple examples of the combined gas law; I need one or two more examples. I was try ing to make an example (for a short paper) of blowing up a ballon, but I can not correlate the variables in the equation for this example.

2007-10-31 08:12:05 · 6 answers · asked by RogerDodger 1