Chemistry - May 2007

i want to start writing my diary and i want it to be a secret what type of invisible ink should i use prefrebly made at home and what is its components

2007-05-27 06:54:07 · 2 answers · asked by ahmedkorra5 1

3-methyl-5methyheptane + hydrogen -------- ethane + propane + methylbutane

2007-05-27 06:43:49 · 2 answers · asked by Yayan 1

For gas laws like PV=nRT, or PV=PV, or P/T=P/T can I use atms, mm Hg, or Kpa for the pressure, or should i always convert into kPa?

2007-05-27 06:42:39 · 6 answers · asked by Anonymous

If you pour half an inch of vinegar into an open cup, can it evaporate in a few days? What if you put a penny in there too?
I

2007-05-27 06:37:15 · 9 answers · asked by Anonymous

2007-05-27 06:25:21 · 4 answers · asked by Anonymous

2007-05-27 06:10:48 · 1 answers · asked by ganesh - 1

And how is the activity series of metals / metal reactivity related to all this?

2007-05-27 04:46:18 · 4 answers · asked by Arielle 1

2007-05-27 04:43:20 · 4 answers · asked by Anonymous

If we have some reactants in all types of states of matter, will that affect the formulas of the products??? If yes, why?

2007-05-27 04:31:38 · 5 answers · asked by Arielle 1

Without balancing, do these reactants yield these products?

a) Al(s) + CuSO4(aq) → Cu(s) + Al2(SO4)3(aq)
b) Hg(s) + AlBr3(aq) → Al(s) + HgBr2(aq)
c) Zn(s) + H2SO4 (aq) → H2(s) + ZnSO4(aq)
d) Ca(s) + MgBr2(aq) → Na(s) + CaBr2(aq)
e) Cu(s) + AlCl3 → no reaction
f) Cl2(aq) + NaI(aq) → Na(s) + ClI(aq)
g) NaCl(aq) + I2 → no reaction

2007-05-27 04:30:02 · 2 answers · asked by Arielle 1

2007-05-27 03:27:29 · 6 answers · asked by suhaila 1

2007-05-27 02:25:21 · 3 answers · asked by Anonymous

My test is coming up soon (in a few days) and so I decided to look at a few pastpapers.
There were two questions I was unsure of even after I was told the answers from the mark scheme.
The paper is June 2005 Paper 1:

Question 22- In an experiment shown, the dilute sulphuric acid is run into the flask of aqueous barium hydroxide until the reaction is complete. Which processes occur in this reaction? A- Neutralisation and Precipitation B- Just Neutralisation C- Just Precipitation D- None. I chose B but the answer is A?

Question 28- Which metal reacts quickly with cold water only when it is finely powdered? A- Calcium B- Copper C- Sodium D- Magnesium. I chose C as sodium is the most reactive out of all of them (according to the reactivity series) but the answer is D?

I would appreciate any help. Thank you!

2007-05-27 02:18:31 · 2 answers · asked by yos_msn 2

urgent,,,its homework and my chem teacher is evil...

2007-05-27 00:23:29 · 2 answers · asked by moshi 1

2007-05-26 22:04:24 · 1 answers · asked by Frederik v 1

2 HCl + Na2SO4 --> 2 NaCl + H2SO4

If you start with 20 grams of hydrochloric acid, how many grams of sulfuric acid will be produced?

and plss give me all the steps to the answer too,,

2007-05-26 20:41:55 · 3 answers · asked by gunkedar 2

I had just asked if it was illegal. the answer was no, so I guess I would like to know where to get it....

2007-05-26 20:36:09 · 3 answers · asked by Worried Rachel 2

2007-05-26 18:29:11 · 7 answers · asked by Anonymous

A little background information: In Greek tradition there is a think called the evil eye, which is sort of a curse that is put on a person. You don't really need details about that. Apparently to find out if someone has the evil eye put on them, you take a glass of water and drip one drop of oil from your fingertip into the water. If the oil stays in globular form (like you would expect, since oil and water don't mix), you're fine. If, however, the oil dissolves, you have the evil eye. You keep dropping until the oil stays globular three times in a row, and then you're said to be cured.

Now personally, I don't believe in silly superstition and I think there's an explination for everything. My grandparents and uncle, however, swear they have witnessed the oil completely dissolving in the water to the point you can't see it at all on multiple separate occasions. They challenged me to find a scientific explination for why this happens. Anyone have any ideas?

2007-05-26 13:07:18 · 2 answers · asked by jennifurret 2

2007-05-26 13:02:16 · 6 answers · asked by aerojanie 1

A 0.20mL sample of blood after dilution gave an emission reading of 27. Solution B and C, containing the same amount of blood plus 50 and 100ppm of K+, respectively, gave reading of 39 and 51. Calculate the ppm of K+ in the blood sample.

2007-05-26 12:35:09 · 2 answers · asked by ilovestirfry 2

Would it make a good alternative fuel and would it work well on cars

2007-05-26 12:01:59 · 1 answers · asked by Anonymous

A mixture had 3 compounds found in the table below.

Compound

soluble in cold water
benzoic acid n
Mg (OH)2 n
Zn(OH)2 n

soluble in hot water
benzoic acid y
Mg (OH)2 n
Zn(OH)2 n

soluble in3M HCl:
benzoic acid n
Mg (OH)2 y
Zn(OH)2 y

soluble in 3M NaOH
benzoic acid y
Mg (OH)2 n
Zn(OH)2 y


After the mixture of the 3 solids was extracted with hot water & filtered, Compound A was obtained by evaporating the filtrate to dryness.
When 3M HCL was added to the solid residue, a clear solution resulted.
After adding excess 3M NaOH solution to the acid solution, a precipitate formed.
After filtration, the insoluble solid was found to be compound B. Compound
C was recovered by evaporation of the filtrate.

What is Compond A, B, and C? and please help with the explanation. Thaks.

2007-05-26 11:59:44 · 3 answers · asked by gym guy 2

High strength floor coating

2007-05-26 11:53:50 · 1 answers · asked by Zeca G 1

High strength floor coating

2007-05-26 11:52:48 · 1 answers · asked by Zeca G 1

PLease HElp

i just made two solutions 1. salt dissolved in water 2. sugar dissolved in water. i put them in seperate jars with a washer inside the jar with a string holding it. Now What do i wait for? Also i put food coloring in one of them, will that ruin the rock candy. Where should i put the two solutions? How long do i have to wait?

Thanks to anyone!!

2007-05-26 11:29:54 · 4 answers · asked by Anonymous

can anyone tell me questions about apples that also relate to chemistry? questions like why apples turn brown? just the question, i dont need the answer... please dont give me a question about why they change color or why some are sour or sweet please becuase i already have those questions...thanx

2007-05-26 09:41:16 · 2 answers · asked by Anonymous

Why does the number of hydrogen atoms in the molecular formula decreases by 2 as you go from alkanes to alkenes and then to alkyns?

2007-05-26 09:01:40 · 5 answers · asked by Yayan 1

2007-05-26 08:25:49 · 1 answers · asked by Anonymous

Hi peeps,

Anyone know the chemical equations for the following:

1) Reaction of butanal with Tollen's reagent

2) Reaction bewteen propanone and Brady's reagent.

Any help with the above would be very much appreciated as I am totally stuck! (I do not know the molecular formula for the two reagents)

Thanks.

2007-05-26 08:11:04 · 2 answers · asked by Anonymous