Chemistry - February 2007

2007-02-25 21:36:32 · 3 answers · asked by Gideon 1

im doing as level chem and i HATE IT!
i cant quit becuse i need it to do the course i want, but i havent been to the lessons for well over a month, what should i do? do you reckon i'll get kicked off the course?
what should i do to make me like it????????

2007-02-25 21:36:22 · 3 answers · asked by superbike 1

I am going to do a chemistry experiment that is about fuels.

My experiment is about burning food and use the energy produced to heat the water. Thus, I can use mc△T to calculate the energy of the food produced.

However, I have a question. I want to know how to reduce the heat loss so that I can ensure most of the heat energy produced by food can go into the water?

P.S. My experiment is like this.
http://www.woodrow.org/teachers/chemistry/institutes/1988/calorimeter.gif

2007-02-25 21:11:13 · 2 answers · asked by T.C. 1

solid x is solube in both hot and cold water
solid y is soluble in hot water but insoluble in cold water
solid z is insoluble in both hot and cold water

how could you seperate solid y from a mixture of solids x, y and z.

2007-02-25 20:57:13 · 2 answers · asked by Anonymous

a-all of it will decay in 7,000 years
b-half of it will decay in 7,000 years
c-it will start to decay in 14,000 years
d-it will no longer be radioactive in 7,000 years

2007-02-25 19:48:57 · 4 answers · asked by sxe 1

I need help with my chemistry homework. I've got a practial to handout, it's about the determination of the avogadro constant. Well the thing is that I don't know how to get my uncertanties after measuring. I've measured time, volts. amperes and temperature.

Thank you....

2007-02-25 19:13:48 · 1 answers · asked by Anonymous

With opposite sex!

2007-02-25 19:02:27 · 2 answers · asked by Katja ie tattybow 1

2007-02-25 19:00:41 · 3 answers · asked by australia_emileah 1

if i hold a magnet up to aluminum will it stick ? what products are aluminum ?

2007-02-25 19:00:15 · 7 answers · asked by ME M 1

they say that if water didn't have these hydrogen bonds it would be a gas. So why are they so strong that it takes a lot of heat to evaporate?

2007-02-25 18:51:28 · 3 answers · asked by avalentin911 2

Buffers and Antacids Experiment: In this experiment, you will make up a series buffer solutions by mixing Vol. CH3COO-mL of 0.500 M acetate and Vol. CH3COOH ml of 0.500 M acetic acid together. I'm to show algebraically why this will always result in :

[CH3COO-]/[CH3COOH]= Vol. CH3COO-/ Vol. CH3COOH

where [CH3COO-] and [CH3COOH] are the equalibrium concentrations in the buffer.

2007-02-25 18:44:07 · 1 answers · asked by shiroi_tora88 1

partscoretotal1--0.1The distinctive odor of vinegar is due to acetic acid, HC2H3O2. Acetic acid reacts with sodium hydroxide in the following fashion: HC2H3O2(aq) + NaOH(aq) H2O(l) + NaC2H3O2(aq). If 2.55 mL of vinegar requires 34.9 mL of 0.1036 M NaOH to reach the equivalence point in a titration, how many grams of acetic acid are in a 1.00 qt sample of this vinegar? (1 L = 1.0567 qt)

____________ g/qt

2007-02-25 18:30:01 · 1 answers · asked by lola_boo 1

2007-02-25 18:23:41 · 8 answers · asked by australia_emileah 1

question#1:

if the temperature is constant, what change in volume would cause the pressure of an enclosed gas to be reduced to one quarter of its original value


question #2:
assuming the gas in a container remains at a constant temperature, how could you increase the gas pressure in the container a hunderfold?

2007-02-25 18:18:58 · 2 answers · asked by cougar66lt 2

For the following electronic transitions in the hydrogen atom, calculate the energy, frequency, and wavelength of the associated radiation and determine whether the radiation is emitted or absorbed during the transition.
(a) from n = 3 to n = 6
____ J (energy)

____ s-1 (frequency)

____m (wavelength)



(b) from n = 9 to n = 3
____J (energy)

____ s-1 (frequency)

_____m (wavelength)



(c) from n = 7 to n = 4
____J (energy)

_____s-1 (frequency)

_____m (wavelength)

2007-02-25 18:06:51 · 3 answers · asked by lsubetty 2

it has six electrons in the last shell so it can get 2 electrons to become stable but our teacher told us that it is unreactive. is it because its more radioactive than its reactivity?

2007-02-25 18:06:22 · 1 answers · asked by . : [ s a k u r a ] : . 3

2007-02-25 17:28:57 · 2 answers · asked by earl 1

1-nonpolar water molecules are attracted to each other more strongly than to oil molecules
2-polar water molecules are attracted to each other more strongly than to oil molecules
3-polar water molecules are attracted to nonpolar oil molecules
4-polar oil molecules are attracted to each other more strongly than to water molecules

2007-02-25 17:23:31 · 2 answers · asked by Anonymous

Indicate the concentration of each ion present in the solution formed by mixing the following.
(a) 26 mL of 0.100 M HCl and 10.0 mL of 0.220 M HCl
H+ : _____ M
Cl- : ______ M

(b) 15.0 mL of 0.300 M Na2SO4 and 20.2 mL of 0.100 M NaCl
Na+ : ____ M
SO42- : ____ M
Cl- : ____ M

(c) 3.50 g of KCl in 60.0 mL of 0.306 M CaCl2 solution (assume that the volumes are additive)
K+ :_____ M

Ca2+ : _____ M
Cl- : _____ M

2007-02-25 17:21:43 · 1 answers · asked by lola_boo 1

2007-02-25 17:17:34 · 2 answers · asked by Anonymous

2007-02-25 17:08:28 · 2 answers · asked by Anonymous

1-changing the direction in which a force is exerted
2-decreasing the amount of force that is exerted
3-decreasing the amount of work that is done
4-changing the distance over which a force is exerted

2007-02-25 17:03:17 · 7 answers · asked by Anonymous

(a) How many grams of solute are present in 50.0 mL of 1.33 M CoSO4?
______g
(b) If 3.00 g of (NH4)2SO4 is dissolved in enough water to form 200. mL of solution, what is the molarity of the solution?
_______M
(c) How many milliliters of 0.460 M NiCl2 contain 1.00 g of solute?
______mL

2007-02-25 16:52:42 · 1 answers · asked by lsubetty 2

2007-02-25 16:46:56 · 7 answers · asked by bubblepower789 2

f-like charges in the atoms cause them to stick together
g-the atoms fit together like two pieces of a puzzle
h-the atoms share or transfer electrons
j- the two atoms combine into a new, larger atom

2007-02-25 16:36:42 · 4 answers · asked by Anonymous

I have a manditory science research project.I would really appreciate it if you could help me out.

2007-02-25 16:31:48 · 1 answers · asked by artluver128 1

All help is greatly appreciated! =)

2007-02-25 16:24:16 · 1 answers · asked by xplozno8 2

The heat of hydrogenation for 1-pentene is –126 kJ/mol when reacting with one mole of H2. Calculate the heat of hydrogenation expected if two moles of H¬2 react with one mole of a pentadiene. The experimentally measured heat of hydrogenation for 1,2-pentadiene is – 296 kJ/mol, 1,3-pentadiene is – 226 kJ/mol and 1,4-pentadiene is – 254 kJ/mol. Explain the order of stability of conjugated, cumulated and isolated dienes using this information.

2007-02-25 16:18:49 · 1 answers · asked by afchica101 1

2007-02-25 16:14:31 · 2 answers · asked by afchica101 1

Determine the mass of each reactant needed to give the indicated amount of product. Be sure that the equations are balanced.
AgNO_3 + CaCl_2 yields AgCl + Ca(NO_3)_2
1.31 mol AgCl find mass of AgNO_3 and CaCl_2

2007-02-25 15:51:27 · 3 answers · asked by me of course 2