Chemistry - January 2007

2007-01-27 23:30:02 · 6 answers · asked by amazing_sweet_angel 1

in relation to saponification

2007-01-27 23:28:34 · 2 answers · asked by amazing_sweet_angel 1

2007-01-27 23:26:53 · 3 answers · asked by roxanne a 1

2007-01-27 22:00:12 · 4 answers · asked by zammoau 1

2007-01-27 20:19:05 · 3 answers · asked by totalangel24 1

2007-01-27 20:15:47 · 2 answers · asked by Kristada 2

wondering if you can give me any more information on depleted uranium or if you can correct me if im wrong because i just started researching this yesterday and i found myself interested in it .. so this is what i have .. there are uranium 235 and 238 isotopes and with nuclear fission uranium 238 can be converted to plutonium? with plutonium u can create nuclear warheads .. children fall victim to depleted uranium due to teh fiery aftermath of nuclear bomb exposions?

2007-01-27 19:44:57 · 6 answers · asked by Anonymous

please also provide good sites as to where i can research these :) thanks. i really am messed up when it comes to biochem lab questions..

2007-01-27 19:41:10 · 2 answers · asked by kaoru kamiya 1

2007-01-27 19:32:52 · 1 answers · asked by Anonymous

Which of the following statements is true (T) or false (F):
(a) All real processes are irreversible
(b) In an irreversible cyclical process, the system returns to its original state, but the universe does not.
(c) All spontaneous processes increase the disorder of the system

2007-01-27 18:59:52 · 2 answers · asked by You6789 1

what is the limiting reactant?

2007-01-27 18:40:54 · 3 answers · asked by Anonymous

2007-01-27 17:36:48 · 1 answers · asked by freaking_naj 1

The most common form of calcium has 20 protons, 20 neutrons, and 20 electrons. Which of the following elements would be an isotope of calcium?
a)an atom with 20 protons, 21 neutrons, and 20 electrons
b)an atom with 20 protons, 20 neutrons, and 18 electrons
c)an atom with 21 protons, 20 neutrons, and 21 electrons
d)all of the above
e) none of the above

2007-01-27 17:02:13 · 6 answers · asked by soccerjock 2

a)forms a covalent bond with another atom
b)becomes part of a molecule
c)is an ion
d)gains or loses a neutron
e)gains or loses a proton

2007-01-27 16:40:26 · 12 answers · asked by soccerjock 2

Since water freezes at zero degree Celsius (or 32 degrees Fahrenheit), let's say I bring a thermo flask with water up to the roof of a 3 storey building during one cold day (say it's -20 degrees outside). I release one drop of water to the ground. Will the drop of water freeze as it falls? Or will it generate enough energy to stay as a liquid before it splats on the ground and then freeze?

2007-01-27 16:39:59 · 6 answers · asked by Lynn 2

Consider a hypothetical atom with an atomic number of 4 and a net electronic charge of +1. It has 4 protons. How many neutrons does this atom have?

2007-01-27 16:30:38 · 8 answers · asked by soccerjock 2

i am doing a science fair project in where i find which liquid makes an egg float but i have to find the density of the liquid. i know that to find the density i have to divide the mass by the volume but i can't do it because i don't know how to find the volume. can you give me an example plz.

2007-01-27 15:55:59 · 5 answers · asked by hearbeat62 2

for chemistry class i have to make a mobile

2007-01-27 15:28:23 · 4 answers · asked by jorge m 1

Choose the the compound with the greatest positional entropy in each case.

a. 1 mol H2 (at STP) or 1 mol H2 (at 100 degrees C, 0.5 atm)

b. 1 mol N2 (at STP) or 1 mol N2 (at 100 K, 2.0 atm)

c. 1 mol H20 (s) (at 0 degrees C) or 1 mol H2O(l) (at 20 degrees C)


How do you know which has a greater positional entropy? Is there a way to determine this?

Help me please!

2007-01-27 15:19:12 · 4 answers · asked by laweezer08 1

what would happen if there is an excess of acid or alkali?

2007-01-27 15:12:25 · 1 answers · asked by thomasian 2

Taking into account the heat of combustion for octane (and its equation):

C8H18(l) + 25/2 O2(g) --> 8CO2(g) + 9H2O(g) ΔH= -5472

And, the heat of combustion for the following reactions:

H2(g) + 1/2 O2(g) --> H2O(g) ΔH= -242 kJ

8C(s) + 9H2(g) --> C8H18 ΔH= ?

C(s) + O2(g) --> CO2(g) ΔH= -394 kJ

Thanks in advance for your help!

2007-01-27 15:08:49 · 1 answers · asked by Random G 3

2007-01-27 14:53:45 · 1 answers · asked by ? 1

2007-01-27 14:42:30 · 2 answers · asked by Anonymous

2H2(g) + O2(g) --> 2H2O(g) ΔH = −486.6kJ

a) A phase change is involved


b) Two moles of hydrogen gas react with one mole of oxygen gas to
produce two moles of liquid water


c) Energy is absorbed by the system, the reaction species


d) If the reaction takes place at constant pressure, q = −483.6 kJ


e) ΔH for reacting four moles of hydrogen gas with two moles of
of oxygen gas is −483.6 kJ

2007-01-27 14:34:38 · 2 answers · asked by Anonymous

Like professional chemist do different things than the chemistry major students? Students read lab manual, write reports or graph on excel. What do the chemist have to do in their daily work period?

2007-01-27 14:34:15 · 5 answers · asked by passive84 1

what is the percent composition of sodium carbonate?

2007-01-27 14:22:19 · 2 answers · asked by moody 1

I've tried to the problem but i don't how (my teacher never explained and the book isn't very helpful)

A 100-mg technetium-99m sample is used in a medical study. How much of the technetium-99m sample remains after 24 hr? the half-life of technetium-99m is 6.0 hr

Thanks in advance!

2007-01-27 14:16:41 · 3 answers · asked by Mia16 3

Please show the balanced equation of NaNO2 + H2SO4 and also show the balanced equation of the decomposition of the acidic product produced. Thanks

2007-01-27 14:12:36 · 1 answers · asked by james w 1

2H2(g) + O2(g) --> 2H2O(g) ΔH = −486.6kJ



Which of the following are true statements for the above chemical reaction ?



a) A phase change is not involved


b) Two moles of hydrogen gas react with one mole of oxygen gas to
produce two moles of water vapor


c) Energy is given off to the surroundings


d) If the reaction takes place at constant pressure, q = −483.6 kJ


e) ΔH for reacting four moles of hydrogen gas with two moles of
of oxygen gas is −483.6 kJ

2007-01-27 13:06:56 · 7 answers · asked by Whatever 1

How much heat (kJ) must be removed in order to change 2.91 moles of steam at 114.0 oC to water at 51.0 oC ?


The specific heat capacity of water vapor is 2.01 J g-1 oC -1


Use a negative sign in your answer if heat is removed.


Enter a numeric answer only, do not enter units.

2007-01-27 13:05:06 · 1 answers · asked by Whatever 1