Chemistry - December 2006

I used a regular thermometer. You can use any type.

2006-12-06 08:16:07 · 2 answers · asked by giictexfxerx :) 2

How many grams of Na2SO4 is needed to prepare a 500.0 ml of an 0.250 molar solution of Na2SO4 (molar mass is 142.06 g/mol

2006-12-06 07:28:50 · 4 answers · asked by Felicia 4

In what proportion should 95% alcohol be mixed with 30% alcohol to make 70% alcohol

2006-12-06 07:10:54 · 1 answers · asked by CookFrNW 3

PLEASE SHOW ME STEP BY STEP OF HOW TO BALANCE EQUATION.

2006-12-06 07:09:07 · 2 answers · asked by Anonymous

If 500gm of dextrose are dissolved in 600ml of water, with the final volume being 1000ml, what is the % strength of the dextrose in the solution?

2006-12-06 07:08:44 · 2 answers · asked by CookFrNW 3

In its ground-state, a H atom absorbs a photon of wavelength 97.20 nm. To what energy level does its electron move?

The answer is 4.


How is this value reached?

Here's what I did:

c=(freq)(wavelength), (3x10^8)/(97.20x10^-9), so freq. = 3.09x10^15 Hz.

Then I used E=hv, (6.626x10^-34)(3.09x10^15), so E = 2.05x10^-18 J(?).

Finally, I plugged it into the energy level equation: 2.05x10^-18 = -B(1/x^2 - 1/1^2), with B = 2.179x10^-18...

The answer I got was 1 - which is incorrect!

I know I made a mistake on the last part, so could anyone please clarify?

2006-12-06 06:49:00 · 2 answers · asked by other_user 2

What do you get when you mix nitric acid with mineral oil?

2006-12-06 06:32:50 · 1 answers · asked by Felicia 4

I need a few good ways to make Carbon Dioxide for my school Science project. Can anybody list a few good ways?

2006-12-06 06:31:17 · 17 answers · asked by Pancake Man 4

Which of the following properties are exhibited by biological membranes?


a.Impermeable to all but small lipophilic and hydrophobic molecules

b.Most proteins are fixed in the plane of the membrane

c.High fluidity, low viscosity

d.Low lateral mobility of lipid molecules

2006-12-06 06:12:14 · 1 answers · asked by Anonymous

I need to know how many electons neutrons and protons are in 3H
14N, 12C, 14C, 10B, 11B, 16O, 16O-2, 7Li, 7Li+1, 5He, 16O, 22F, 2H, 22Ne, 23Na. Please help out i have no clue how to do this stuff. Thanks alot

2006-12-06 05:59:02 · 4 answers · asked by stanmorodokhin 1

Which of the following chemical equations describes the release of energy by the body's main energy-releasing reaction?
A.C6H12O6+ 6 O2 --- > 6H2O + 6 Co2 + 2.87 X 10^3 kJ
B.Energy + ADP+HPO4^2- --- > H2O +ATP
C.2 H2O2--- > 2 H2O + O2 + Energy
D.H2CO3 --- > H20 +CO2

2006-12-06 05:51:28 · 3 answers · asked by cetinnovations 1

a) CH3COOH(aq) + NH3(aq) = CH3COO-(aq) + NH4 +(aq)

b) Cu 2+(aq) + 4NH3(aq) = Cu(NH3)42+(aq)

c) Al(OH)3(s) + OH-(aq) --> Al(OH)4-(aq)

d) AgCl(s) + 2NH3(aq) --> (NH3)2Ag+(aq) + Cl -(aq)

2006-12-06 05:50:05 · 1 answers · asked by Kel 1

a) HCl : A Bronsted acid and a Lewis acid

b) HN3 : A Bronsted base, but not a Lewis base

c) CH3COOH : A Bronsted acid and a Lewis acid

d) Ni 2+(aq) : A Bronsted acid, but not a Lewis acid

e) CH3CH2CH2CH3 : Neutral, not an acid or base of any kind

2006-12-06 05:46:27 · 2 answers · asked by Whatever 1

I'm a bit stumped on this one...

2006-12-06 05:40:16 · 1 answers · asked by Random G 3

2006-12-06 05:26:36 · 10 answers · asked by Anonymous

2006-12-06 05:05:52 · 4 answers · asked by ~kool-aid~ 1

Im working on a lab and I am stumped on how to find specific heat. I have water and 100g Iron Fe at a Intial tempature of 20c and I place the iron fe in a test tube and heat it inside of a beaker with 150ml of H20 which is at 20c as well. I heat it untill the iron fe and water has reached both 100c and place the Iron Fe into a Calorimeter filled with 100ml of H20 at 20c as well. Once I place the 100g of Iron Fe at 100c into the Calorimeter the tempature of the water goes up to 28c. How am I supposed to find the specific heat of Fe using that senario can anybody please help!!! Thank you in advance

2006-12-06 04:58:08 · 2 answers · asked by Anonymous

a) NH3 : A Bronsted base, but not a Lewis base

b) OH - : A Bronsted base and a Lewis base

c) CH3COOH : A Bronsted acid, but not a Lewis acid

d) Cu 2+(aq) : A Bronsted acid, but not a Lewis acid

e) CH3CH2CH2CH3 : Neutral, not an acid or base of any kind

2006-12-06 04:55:58 · 2 answers · asked by Anonymous

a) Ag +(aq) + 2NH3(aq) = Ag(NH3)2 +(aq)

b) 2HCl(aq) + Ca(OH)2(aq) --> CaCl2(aq) + 2H2O(l)

c) Al(OH)3(s) + OH-(aq) --> Al(OH)4-(aq)

d) BF3(g) + (CH3CH2)2O(l) --> (CH3CH2)2OBF3(l)

2006-12-06 04:54:35 · 2 answers · asked by Anonymous

2006-12-06 04:51:14 · 9 answers · asked by ~kool-aid~ 1

2006-12-06 04:15:13 · 3 answers · asked by lala haha gaga mama 2

a) H2PO4(-) + H2O = HPO4(2-) + H3O(+) H2PO4- is the Lewis acid


b) HClO4 + H2O ---> H3O(+) + ClO4(-) HClO4 is the Lewis base


c) H2PO4(-) + H2PO4(-) = H3PO4 + HPO4(2-) H2PO4- is both the Lewis base and the Lewis acid


d) HCl + H2O ---> H3O(+) + Cl(-) Water is the Lewis base


e) Fe(H2O)6(3+) + H2O = Fe(H2O)5(OH)(2+) + H3O(+) Fe(H2O)63+ is the Lewis acid



you must enter all true statements in one alphabetical lower case group
e.g., if a) b) and e) are true you would enter abe

2006-12-06 03:55:58 · 2 answers · asked by dannyg11us 1

2006-12-06 03:42:16 · 6 answers · asked by messy j 1

What is the physical basis for the VSEPR model?

When applying the VSEPR model, we count a double or triple bond as a single electron domain. Why is this justified?

2006-12-06 03:31:29 · 1 answers · asked by bosox1989 1

If the valence atomic orbitals of an atom are sp hybridized, how many unhybridized p orbitals remain in the valence shell? How many pie bonds can the atom form?

How many sigma molecular and pie bonds are generally part of a triple bond

How do multiple bonds introduce rigidity into molecules?

2006-12-06 03:29:41 · 1 answers · asked by bosox1989 1

A 100. mL sample of 0.200M aq hydrochloric acid is added to 100. mL of 0.200 mL aq ammonia in a calorimeter whose heat capacity(excluding any water) is 480 J/K. The following reaction occurs when the two solutions are mixed.

HCl(aq) + NH3(aq) --> NH4Cl(aq)

The temperature increase is 2.34C. Calculate change in heat per mole of HCl and NH3 reacted?

2006-12-06 03:07:18 · 2 answers · asked by jess 1

2006-12-06 02:58:52 · 1 answers · asked by cece 2

2006-12-06 02:46:55 · 1 answers · asked by cece 2

2006-12-06 02:27:39 · 1 answers · asked by Anonymous

2006-12-06 02:07:22 · 7 answers · asked by teju 1