Chemistry - October 2007

if u had a pot of cold water..would u reach a boil faster than if u started with hot water.all variables being the same.

2007-10-24 18:08:05 · 2 answers · asked by bob t 1

1. CH3 OH + O2 --> CO2 + H2 O

2. Al + HNO3 --> H3 + Al(NO3)3

3. (NH4)2 Cr2 07 --> Cr2 O3 + N2 + H2O

All of the numbers go below the previous letter. Like H(2 below) and O

2007-10-24 17:31:58 · 2 answers · asked by Leeler 1

Ok, I seriously need this ASAP.

the question says, The density of methanol is 0.796 g/cm3. Is 4.00 mL of methanol a satisfactory volume to use in this experiment? Justify your answer with a calculation.

THe only thing I have for methanol is its molecular weight, 49.28 g/mol.

But I dont have the temperature of the REQUIRED moles of methanol!!! how am i supposed to do this??? This is what I did:

Since, density = mass/volume
0.796g/cm3 = mass / 4cm3
Mass= 3.184 g

Further, number of moles = mass / molar mass
n = 3.184 g / 49.28 g/mol
n= 0.06448 mols

To find the required number of moles, we use the ideal gas law:
PV = nRT
n = PV/RT (T ???)
n =

and what about the volume?? All i know is that the molecular weight of the IDEAL/ required methanol is 32.04 g/mol

HELP ME FOLKS PLEASEEE QUICK. THANKSSS

2007-10-24 16:53:35 · 3 answers · asked by Curious 1

1. Do the constant volume and constant pressure heat capacities apply for solids and liquids or for gases/(ideal gases?) only?

2. In calculus, what is the difference between d and (delta)? Using entropy, what would be the difference between dS and (delta)S. Also what does the backward looking "6" represent in partial derivatives {ex: partial f/partial x when you have f(x,y)}?

3. How is calculating (delta)H and (delta)U different for solids and liquids that it is for ideal gases?

2007-10-24 16:47:36 · 1 answers · asked by bob oso 2

Let's say, I have H_2O, BF_3, CH_4, NaF, and HF. How do I figure out which substance has the highest melting point?

Thank you

2007-10-24 16:41:13 · 2 answers · asked by guyava99 2

I have to make a model of an atom of Iodine. It doesn't have to be edible, but I would like it to be, since we get extra credit if it is. What should I make it out of? BTW: It has to last allll day since science is my last period class.

2007-10-24 16:17:10 · 3 answers · asked by Liz P 2

help please!

2007-10-24 15:45:23 · 6 answers · asked by Anonymous

I have to think of a creative way to pretend to be a salesman and sell it........

humor would be appreciated but only up to 8th grade humor....

2007-10-24 15:13:29 · 5 answers · asked by Anonymous

A solution is prepared by adding 57.0 mL of 0.050 M HCl to 143.0 mL of 0.30 M HNO3. Calculate the concentrations of all species in this solution.
[H+]

[OH -]

[Cl -]

[NO3-]

2007-10-24 15:13:08 · 1 answers · asked by denver007 2

2007-10-24 14:33:44 · 9 answers · asked by jordancross17 1

I have an experiment to neutralize CaCO3 with HCl by titration (titrationg HCl into a CaCO3 solution). I dissolved an antacid tablet with 1000mg of CaCO3 in it into water and according to my calculations it would take about 167mL of 0.030mol/L hydrochloric acid to neutralize it (used phenophthalein as an indicator- waited for it to turn from pink in the CaCO3 solution back to colorless). However when I actually did the titration my titration values ranged from 1.2 mL-2.1mL with the consistent values at about 1.9 mL, well short of what I expected. Does anyone know if there is some sort of hidden reaction or something which causes results to go weird? For my stoich calculation i used CaCO3 + HCl --> CaCl2 + H20 + CO2
thanks

2007-10-24 14:18:00 · 3 answers · asked by snorlax_nick63 2

what are carbon compunds? what are the types in food that give energy as calories?

2007-10-24 13:45:40 · 2 answers · asked by Anonymous

i really need to know but please be easy in what you say i am in 8th grade.

2007-10-24 13:42:25 · 3 answers · asked by Manu Ginobili 1

2007-10-24 13:36:01 · 1 answers · asked by nayapar 3

2007-10-24 13:33:49 · 3 answers · asked by Bite Me 4

Cr + CrO4 -> Cr(OH)3

Why/how is hydroxide formed in this reaction? Is it because you need hydrogens to add positive charge so that Cr can maintain its +3 oxidation state? Thank you for any help.

2007-10-24 13:30:22 · 1 answers · asked by anovelidea24 3

2007-10-24 13:26:00 · 2 answers · asked by nayapar 3

During a moon landing, one of the experiments performed was the measurement of the intensity of solar wind. As a collector, an aluminum strip of about 3,000.000 square centimeters was used. It was found that in 100.00 minutes, a mass of 3.00 x 10^-10g of hydrogen was collected. What is the intensity of the solar wind (number of atoms per sq. centimeter per second?).

2007-10-24 12:57:06 · 1 answers · asked by Caramel 2

2007-10-24 12:39:36 · 4 answers · asked by sweetngel 1

Don't tell me there the same thing because according to a Chem ditto I'm doing there not. Also how do you find them on the Periodic Table. Thanks!

2007-10-24 12:12:25 · 5 answers · asked by Melissa S 2

I was given the following question:

a) carbon tetrachloride (CCl4)
b) glycerol (C3H5OH3)
c) ethene (C2H4)
d) ethyne (C2H2)
e) quartz (SiO2)
f) diamond (C)
g) Na
h) KI
i) CsF
j) He

Which of the above:
(i) exhibits only van der Waals forces?
(ii) cleaves into definites cleavage planes when the solid crystal is distorted?
(iii) is a nonpolar molecular substance?
(iv) conducts electricity at room temperature in solid state?
(v) exhibits hydrogen bonding?
(vi) conducts electricity when melted?
(vii) is a network solid?

I am having difficulties with this question, so I would appreciate if anyone could explain the answers and the reasons.

Thank you!

2007-10-24 11:52:45 · 1 answers · asked by jade832 2

2007-10-24 11:41:06 · 1 answers · asked by birmingham927 2

60 Calories is added to 1 gram of water at an initial temperature of 80 degrees Celcius. What is the water's final temperature and state (solid, liquid, or vapor)?

2007-10-24 10:56:04 · 1 answers · asked by qtbabymin 1

who developed theory of atomic power?

2007-10-24 10:31:20 · 1 answers · asked by blackfootprincess1 1

(A) O(B) B(C) C(D) Li(E) Ne(F) N

2007-10-24 10:31:05 · 3 answers · asked by Anonymous

How do you calculate the pH of a solution at saturation when given the insoluble salt and its Ksp?

2007-10-24 10:27:57 · 2 answers · asked by Tiffany 4

2007-10-24 10:19:40 · 3 answers · asked by Anonymous

[H+]=??
[OH -]=??
[Cl -]=??
[NO3-]=??

2007-10-24 10:16:14 · 2 answers · asked by Joshua K 1

pH = 7.40
[H+]=??
[OH -]=??

pH = 15.1
[H+]=??
[OH -]=??

pH = -1.0
[H+]=??
[OH -]=??

pH = 1.61
[H+]=??
[OH -]=??

pOH = 4.0
[H+]=??
[OH -]=??

pOH = 8.52
[H+]=??
[OH -]=??

2007-10-24 10:13:56 · 1 answers · asked by Joshua K 1

If 1.50 mL of 0.69M NH3 areadded to 1.0 L of 1.0 X 10^-3M FeSO4 and a percipitate forms, how do you calculate Q?

I tried
Q=[Fe][SO4]=(1.0 X 10^-3)^2=1.0 X 10^-6
What did I do wrong?

2007-10-24 10:08:43 · 1 answers · asked by Tiffany 4