Chemistry - April 2007

want to know how much and of what substance to add to 1 liter of water to lower it's freezing point to about -12C - ideally it would be non toxic - but preferrence is on ease to mix the substance in and cost (table salt doesn't work for my application) - the end solution must be clear. Thanks

2007-04-30 03:42:24 · 2 answers · asked by Anonymous

The water is purified through series of softner and then store in stainless steel tank.

2007-04-29 22:36:14 · 2 answers · asked by Anonymous

Explain you answer.

2007-04-29 22:31:11 · 6 answers · asked by twinkled1990 2

I have had a kerosene spill under my house from a kerosene pipe. I believe there is kerosene under my house causing an odour I cannot move. I realise kerosene eventually evaporates but there would appear to be quite a quantity under the house and I am looking for a solution other than digging up the whole ground floor of my home ! The pipework that leaked is still in place but now disconnected. I have devised a plan to pour a chemical through the pipework to reach the kerosene where it has leaked in an attempt to neutralise it / break it down. Could anyone suggest a chemical / solution / compound that destroys / breaks down kerosene leaving no smell ? Please help !

2007-04-29 22:25:09 · 4 answers · asked by kerosene help ! 1

a. Pb2+, Zn2+
b. Cu2+, Zn2+
c. Ca2+, NH4
d. Phosphate, sulfate
e. Iodide, bromide
f. carbonate, thiocyanate
Tnx guys..

2007-04-29 22:00:27 · 1 answers · asked by Rubieanne 1

The book says "A molecule is a group of 2 or more atoms chemically joined together." so when it says 2 or more, does it mean:
in terms of numbers or
in terms of types???

2007-04-29 21:52:11 · 6 answers · asked by halokawayee 1

This is done during titration.

2007-04-29 21:27:52 · 5 answers · asked by twinkled1990 2

...i was doing a research for my thesis nxt year in our research 2 subject. and i "chitin" got my interest as my potential research proposal...my only problem is to find a methodoogy or process on how can i extract chitin from crab shell when i know that crab shell has also other compounds besides chitin. i hope you can help me with this..

2007-04-29 21:20:01 · 2 answers · asked by rhiza 1

Reaction: 4 NH3 + 5 O2 > 4 NO + 6 H2O

2007-04-29 21:03:07 · 2 answers · asked by Anonymous

If I have the extinction coefficient of the individual proteins in a solution do I then add them all up to find the total for the solution

2007-04-29 20:38:57 · 1 answers · asked by jason 1

and 12.1 grams CuSO4? the actually amount if CuS produced was 3.05 grams REACTION: Na2S + CuSO4 > Na2SO4 + CuS

2007-04-29 20:08:38 · 1 answers · asked by alicia r 1

Question:

(a) What is the entropy of a perfect crystal at 0 K?
(b) Does entropy increase or decrease as the temperature rises?
(c) Why is H(enthalpy) = 0 but S(entropy) > 0 for an element?

My Approach:
(a) I really have no idea...We weren't provided any info about the perfect crystal (even though the temp was given)
(b) entropy increases b/c it approaches vaporization?
(c) non-spontaneous? i really have no clue here.

Thanks to those who provide me the extra help I need to get through this only question I have from my homework!

2007-04-29 20:07:11 · 1 answers · asked by Jimmy 3

under certain conditions the reaction will proceed at 29.8% yield of NO How many grams of NH3 must be made to react with excess oxygen to yield 70.5 grams NO???






















under certain conditions the reaction will proceed at 29.8% yield of NO. How many grams of NH3 must be made to react with excess oxygen to yield 70.5 grams of NO.

2007-04-29 19:57:01 · 2 answers · asked by alicia r 1

The first person to response will be offered 10 points.

2007-04-29 19:31:11 · 2 answers · asked by Anonymous

2007-04-29 19:29:33 · 1 answers · asked by Anonymous

2007-04-29 19:22:51 · 3 answers · asked by Anonymous

Will they ask me to draw a Lewis structure of a complicated molecule like...CH2ClCOO-?
Because for the more complex molecules, I am so clueless when it comes to finding the central atom and even finding the right skeletal structure (which atoms are next to which).

If the AP test DOES ask us to draw lewis structures for the more complex molecules, how do you find the skeletal structure?
Or.. will I have to draw every possibility and use formal charges to find the most plausible one?

I'm fine at assigning electron bonds and lone pairs, but finding which atoms bond to which confuses me. especially when theres alot of different atoms to deal with.
Will I have to be able to do that on the AP test?
If so, HOW DO I DO IT?!

[AP test in like.. 2 weeks. panic panic panic. @_@]

2007-04-29 19:22:43 · 3 answers · asked by shugo 3

8HNO3 + 6KI>>>3 I2 + 2NO+6KNO3+4H2O

2007-04-29 19:17:17 · 2 answers · asked by TinaMarie 1

2007-04-29 19:07:23 · 1 answers · asked by Anonymous

1. Ethene

2. Propene

3. 1-Butene

2007-04-29 19:04:53 · 0 answers · asked by Anonymous

here is the question:
what compound if any, will precipitate when 150mL .004M barium hydroxide is mixed with 50mL .003M iron(III) sulfate? determine concentration of all the ions when the mixture reaches equilibrium. Ksp for BaSO4 is 1.5x10-9 and Fe(OH)3 is 4x10-38.

2007-04-29 18:49:21 · 3 answers · asked by jason l 1

2007-04-29 18:40:34 · 1 answers · asked by julie r 1

2007-04-29 18:38:30 · 2 answers · asked by julie r 1

Calculate the acid ionization constant, ka, of a weak monoprotic acid a 1.0 M solution of which has an hydronium ion concentration of 4.18x10^-3 M.

does ka=(4.18x10^-3) (4.18x10^-3) / (what do i put here?)


Can anyone help me with this and please explain the process? thanks!

2007-04-29 17:59:54 · 2 answers · asked by dconeg21 1

2007-04-29 17:36:54 · 8 answers · asked by Anonymous

my son asked me this question and I couldn't answer it, so I'm putting this out to the knowledgeable people of Yahoo Answers!!!!

2007-04-29 17:08:44 · 14 answers · asked by ♪ ♫ ☮ NYbron ☮ ♪ ♫ 6

What are the various PROBLEMS facing hydrogen fuel cell technology??

What are the various OBSTACLES facing hydrogen fuel cell technology??

2007-04-29 17:00:26 · 7 answers · asked by -Gentz - 1

2007-04-29 16:46:10 · 2 answers · asked by Anonymous

What happens when Calcium (the solid) reacts with hydrpchloric acid... any interesting reactions ....what happens when you work with this combiniation etc....( This is for thesis project)

2007-04-29 16:43:25 · 1 answers · asked by Mike M 1

What is the balanced net ionic equation for the reaction below in acidic solution? Enter the coefficient for each substance. Do not leave any answer box blank. Enter 1 if appropriate, or 0 (zero) if the substance does not appear on that side of the equation.
Mn2+ + BiO31- + H1+ + H2O
Bi3+ + MnO41- + H1+ + H2O

2007-04-29 16:41:42 · 3 answers · asked by sakinah_123 1