Chemistry - March 2007

2007-03-31 00:39:08 · 3 answers · asked by Anonymous

2007-03-31 00:24:27 · 2 answers · asked by Anonymous

2007-03-30 22:15:36 · 6 answers · asked by Me + Me = BANG! 2

in my homework i have to calculate each of the following quantities in 0.190 mole : ( C3H5)2O....in problem one i have to find mole of C and i keep getting it wrong.

2007-03-30 22:12:39 · 4 answers · asked by orange_crush_05 6

A sample of 20.0 milliliters of a 0.100-molar HCN solution is titrated with a 0.150-molar NaOHsolution. (Ka HCN=6.2 x 10^-10).
a)What volume of NaOh is used in the titration in order to reach the equivalence point?
b)What is the molar concentration of CN- at the equivalence point?

2007-03-30 21:15:31 · 3 answers · asked by ESTHEFANNY 2

the human body ``burns'' glucose C6H12O6 for energy. Burning 1.3 g of glucose produces 20.4 kJ of heat. What is the molar heat of combustion of glucose

2007-03-30 20:54:49 · 1 answers · asked by bollocks 2

A 25.0 mL sample of 0.100 M HNO3 is titrated with 0.100 M NaOH. Calculate the pH of the solution before the addition of NaOH and after the addition of (a) 25.0 ML (b) 30.0 mL of NaOH.

2007-03-30 18:05:17 · 3 answers · asked by Anonymous

IO- + N2H5+ ------> I2 + NO3-

2007-03-30 17:14:57 · 2 answers · asked by Anonymous

Is the correct??? how can we do that??

2007-03-30 16:44:53 · 4 answers · asked by vartanch 2

2007-03-30 15:41:21 · 4 answers · asked by Ron Mexico 1

We have to answer this question for some chemistry homework due tonight... I thought I understood it- and I thought I was doing it the right way.. Its below:

What is the boiling point of 0.500 m lactose in water?

I was doing T(delta T/ change)= 1(1.86)(.5)
I got .93, and and then added it to 100 degrees C, and got 100.93. The quiz thingy keeps telling me the answer is wrong. Am I doing anything wrong?

2007-03-30 15:16:34 · 1 answers · asked by countrygurl587 3

Convert to calories (C)
I did the converting (J ---> cal. = 4.184 J / 1 cal.) and I got 8126 cal.

How do I round the problem correctly?

2007-03-30 14:56:37 · 2 answers · asked by Anonymous

For the reaction
NH3 + O2 → NO + H2O
how many moles of H2O are produced from the complete reaction of 2.18 moles of NH3 ?

For the reaction
SO2 + O2 --> SO3
how many grams of SO2 are needed to completely react with 64.00 g of O2 ?

2007-03-30 14:08:36 · 1 answers · asked by mimi 1

helpppppp pleaseeee!!!!!!!!!

2007-03-30 12:52:17 · 1 answers · asked by rebelcutie 1

2007-03-30 12:22:41 · 4 answers · asked by christine2550@sbcglobal.net 2

I have read even in National Geographic that telfon pans with PFOA might be carcinogenic. Can anyone clarify this some more, or give me a better answer about teflon pans and the dangerous proposed?

2007-03-30 11:39:10 · 4 answers · asked by grantaloon27 2

please in scientific terms

2007-03-30 11:29:39 · 5 answers · asked by lposs89 1

What is the pH of a solution prepared by mixing 71.0 mL of 0.0298 M NaOH and 89.0 mL of 0.0263 M Ba(OH)2?
Any help would be appreciated!!

2007-03-30 11:20:33 · 1 answers · asked by Kyle M 1

My friend and I talked this subject over the other day, but I'm still curious. I know that there IS no such thing as Carbon Trioxide or Cardon Tetroxide, and that such a thing can't be made because the extra oxygen (or is it carbon?) atoms would break off. I have a very inquiring mind, so please help if you can!

2007-03-30 11:13:59 · 4 answers · asked by Helena 2

what is the chemical formulas for ..
magnesium iodide
tin (II) sulfide
barium sulfite
bismuth(III) sulfate
lead(II) acetate-3-water
and the IUPAC NAMES for ..
KC6H5COO(s)
NH4HCO3(s)
LiCl4H2O(s)

2007-03-30 11:13:02 · 2 answers · asked by miss_xbebe 1

I took General Chemistry a while ago, and haven't had to do many titration calculations since then, and I can't remember how to solve this problem.

In a titration experiment, 20.4mL of .883M HCOOH neutralize 19.3mL of Ba(OH)2. What is the concentration of the Ba(OH)2 solution?

Any help here is greatly appreciated, thanks!

2007-03-30 10:59:34 · 2 answers · asked by Anonymous

Given the following heats of combustion.
CH3OH(l) + 3/2 O2(g) CO2(g) + 2 H2O(l) H°rxn = -726.4 kJ
C(graphite) + O2(g) CO2(g) H°rxn = -393.5 kJ
H2(g) + 1/2 O2(g) H2O(l) H°rxn = -285.8 kJ

Calculate the enthalpy of formation of methanol (CH3OH) from its elements.
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I don't know how to set this problem up and/or solve it. Please explain how you set up the problem and determined the answer.

2007-03-30 10:58:18 · 1 answers · asked by Anonymous

Consider the following reaction

CH4 + 2 O2 ===> CO2 + 2 H2O

27.3 grams of CH4 will produce How many Grams of H2O

2007-03-30 10:46:58 · 3 answers · asked by adam b 1

Write the conjugate pair to the acids and bases.
a) PO4^-3 (charge of -3)
b) H2S
c) NH3
d) C3H5O2^-1 (charge of -1)

2007-03-30 08:17:03 · 4 answers · asked by Anonymous

Ka = 7.2 x 10^-4

2007-03-30 08:14:57 · 1 answers · asked by Anonymous

If the following substances were mixed with water would the pH be smaller than, larger than, or equal to 7?
a) CuCl2
b) CaCO3
c) KCl
d) Al(NO3)3

2007-03-30 08:12:58 · 1 answers · asked by Anonymous

For this project, my class has to make stuffed moles and name them something that has "mole in the title"
For example:

"Mole"opoly Man, like monopoly

The "Mole"sen Twins, like Olsen

Ca"Mole", like camo, for camoflouge

Any ideas????

2007-03-30 08:04:26 · 11 answers · asked by gabster 2

1. Why?
2. What is the formula for this compound?
3. If the halide is found to have 44.73% Cl, what is the empirical formula of the compound?

2007-03-30 07:42:53 · 4 answers · asked by TwEeTy_576 1

A monotomic ion has a charge of +2. The nucleus of the parent atom has a mass number of 55. If the number of neutrons in the nucleus is 12 times that of the number of protons, what is the chemical symbol of this element?

2007-03-30 07:34:23 · 4 answers · asked by crazymonkey 1

Na2SO4, Na2CO3, KHSO4, KF, BaCl3, NH4NO3

2007-03-30 07:26:46 · 3 answers · asked by Timeless 2