Chemistry - December 2007

If a 70.3 kg person eats one 40.9 g brownie with nuts, how many minutes would it take for the person to walk off all the calories in the one brownie ? Walking requires energy equal to 2.5 times the basal metabolic rate.

Do NOT consider the energy needed to digest, absorb, and metabolize the snack itself, which the text describes as 10% of the ingested amount of food. Use the total amount of the energy in the one brownie in your calculation.

2007-12-10 09:38:38 · 4 answers · asked by Liv 2

Breaking my brain to figure this one out:

A 2.00g sample of an unknown metal, M, was completely burned in excess O2 to yield 0.02224 mol of the metal oxide M2O2, what is the unknown metal?

So far, I've run in circles and only managed to figure out that the reaction would have to be something like 4M+3O2--> 2M2O3 any hints as to how to begin solving this would be greatly appreciated.

2007-12-10 09:27:24 · 2 answers · asked by Anonymous

Hint: around 450 B.C.E????

2007-12-10 08:59:54 · 4 answers · asked by Max S 2

I need to show an example problem of ethanol using stochiometry. Like show how much carbon was made into a reaction. I am lost, please help.

2007-12-10 08:58:15 · 10 answers · asked by Todd C 1

2007-12-10 08:45:19 · 4 answers · asked by Nana Ama H 1

2007-12-10 08:44:31 · 5 answers · asked by Nana Ama H 1

in forming chemical bonds, atoms tend to attain:
a. higher state of energy
b. electron configuration of noble gas
c. electron configuration of halogen
d. all of the above

2007-12-10 08:42:56 · 2 answers · asked by madery23 1

chemical properties are determined by:
a. energy levels
b. period number
c. number of neutrons
d. number of valence electrons

2007-12-10 08:41:25 · 6 answers · asked by madery23 1

for ammonia, the enthalpy of fusion is 5.65 kJ/mol and an entropy of fusion is 28.9 J/K. mol. What is the melting point of ammonia? How do i start off?

2007-12-10 08:30:53 · 1 answers · asked by Anonymous

also known as black powder...

2007-12-10 08:26:11 · 11 answers · asked by Anonymous

Do I divide it by the volume and that gives me the mass which would help me find the element?

The Density is 8.2 g/cm^3 and the volume is 1.04 ml, I found the mass to be 8.5 grams, would that be Beryllium, even though Beryllium's mass is over 9? Please help?!
Thanks!

2007-12-10 08:01:48 · 1 answers · asked by Anonymous

"Cu2"+ + Mg --> Cu + Mg2+

2007-12-10 07:52:51 · 3 answers · asked by Anonymous

For many years, drinking water has been cooled in hot climates by evaporating it from the surfaces of canvas bags or porous clay pots. How many grams of water can be cooled from 35°C to 25°C by the evaporation of 38 g of water? (The heat of vaporization of water in this temperature range is 2.4 kJ/g. The specific heat of water is 4.18 J/g·K.) Answer should be in KJ.

2007-12-10 07:43:02 · 2 answers · asked by Karma564 2

1.0 mole of C atoms
1.0 mole of water molecules
2.0 moles of H2 molecules
0.5 mole of Kr atoms

2007-12-10 07:40:46 · 3 answers · asked by Anonymous

Is neon gas a man made gas or a gas that comes from within the earth?

2007-12-10 06:52:05 · 3 answers · asked by Girl 4 God 3

which of the following ions has a noble gas electron configuration?
A) Cr3+
B) Fe3+
C) Cu2+
D) S2-
E) Zn2+
thank you for any help:)

2007-12-10 06:10:16 · 3 answers · asked by bocabrunette714 1

2007-12-10 05:38:32 · 2 answers · asked by Yoyo Y 1

I know you find the volumn of an irregular of an irregular object by water diplacement, but how do you find the density? Is it water displacement?

2007-12-10 03:55:28 · 4 answers · asked by alex96100 1

Which statement is true about an electron microscope?

a)The specimen must be dead
b)It magnifies to 2000x
c)It uses glass lenses
d)It is illuminated by light

2007-12-10 02:44:50 · 3 answers · asked by Anonymous

2007-12-10 02:20:40 · 2 answers · asked by Becky 1

ok so here is the chemistry problem i have been working on...and cant seem to figure out...any ideas anyone on how to complete and answer this problem??

Calculate the wavelength of a photon emitted from an atom which had an electron leave the third quanta level and return to the second level.

2007-12-10 02:11:16 · 3 answers · asked by Riley 1

2007-12-10 02:07:55 · 1 answers · asked by Anonymous

2007-12-10 01:59:37 · 1 answers · asked by tory t 1

K2SO4(aq)+ Ba(NO3)2(aq) Ba(SO4)(s)+ KNO3(aq)


HCl(aq)+ Zn(s) H2(g)+ ZnCl2(aq)


HCl(aq)+ AgNO3(aq) HNO3(aq)+ AgCl(s)


HCl(aq)+ KOH(aq) H2O(l) + KCl(aq)


Na(s)+ Cl2(s) NaCl(s)

H2SO4(aq)+ NaOH(aq) H2O(l)+ Na2SO4(aq)

2007-12-10 01:40:32 · 3 answers · asked by Anonymous

yeah,,,Its a relatively easy question,,but most of the chemists don't know why...so why does an electron know where to go..even students have a hard time telling 1s1,2s2 2p6 etc...

2007-12-10 00:04:16 · 6 answers · asked by AskMe 2

2007-12-09 20:58:22 · 1 answers · asked by Anonymous

have been in the ground for 100 million years, what fraction of the initial C-14 atoms is still there? (t1/2 = 5,370 yrs)

a. 0
b. 1 x 10^[-]10
c. 5.7 x 10^[-]5
d. 1.0 x 10^[-]3
e. 5.7 x 10^[-]1

Not sure how to answer this. Could you please show me the steps in your result so that I'll have a greater understanding of the problem?? (TIA)

2007-12-09 19:08:47 · 4 answers · asked by xxxladyxxx 1

Can you help me write a chemical reaction equation ( EX. Au+ Ag --> blah blah) to these balanced ( I know this is a lot so u don't have to answer all four but if u could that would be great)

*Iron - Fe (III) ( 3+) + thiocyanate ( charge -1) -->*

*calcium- Ca (2+) + oxalate ion- C2O4 (-2)-->*

*Silver- Ag (+1) + Chloride- Cl (-1) ---->*

*Copper (II) Cu ( 2+) + Phosphate- PO4 (-3) ---->*


THANK YOU!

2007-12-09 18:33:44 · 3 answers · asked by Yuki 2

an ideal gas at 7c is in a spherical flexible container having a radius of 1.00cm. The gas is heated at constant pressure to 88c. Determine the radius of the spherical container after the gas is heated. Thanks a lot for helping me understand this problem.

2007-12-09 18:15:08 · 2 answers · asked by Anonymous

2007-12-09 17:35:09 · 4 answers · asked by liloofar 3