Chemistry - December 2006

Carbohydrates are compounds containing carbon, hydrogen, and oxygen in which the hydrogen to oxygen ratio is 2:1. A certain carbohydrate contains 40.0 percent carbon by mass. Calculate the empirical and molecular formulas of the compound if the approximate molar mass is 178 g.

2006-12-30 12:09:12 · 3 answers · asked by Luciya 2

A certain metal oxide has the formula MO where M denotes the metal. A 39.46-g sample of the compound is strongly heated in an atmosphere of hydrogen to remove oxygen as water molecules. At the end, 31.70 g of the metal is left over. If O has atomic mass of 16.00 amu, calculate the atomic mass of M and identify the element

2006-12-30 12:06:16 · 2 answers · asked by Luciya 2

For chemistry class we have a project to do.

We hve to make a 3dimensional model of the element we chose.
I chose Krypton.

But im not exactly sure how its suppose to look. And i dont wanna start and then mess up down the line.

I also have to make a 3 dimensional model of the ion from Krypton too.

I have Chemistry first period so i kinda slept this whole semester and im not sure how its suppose to look.

I just know its like different sized rings with a different amount of balls per ring.

But im not sure how many are suppose to go on each ring.

Please and Thank You for the help :D

2006-12-30 12:04:32 · 3 answers · asked by e r ! c k 2

2006-12-30 12:02:11 · 6 answers · asked by 2Quinn 2

2006-12-30 12:01:44 · 2 answers · asked by darshan 1

I have a question that I do not how to solve it even with the answer from the solution manual. CAn someone please explain to me on how to solve it. Thank You. (Happy New Year!)

Q: Acetylene is a hydrocarbon with molecular formula C2H2. Which of the following mass %'s could correspond to another hydrocarbon according to the law of multiple propotions?

A: 85.6% C, 14.4% H

2006-12-30 11:56:28 · 1 answers · asked by AUNIDLY 1

1. (Esters) are capable of forming hydrogen bonds.

2. Esters have (lower) boiling points than alcohols.

2006-12-30 11:54:30 · 4 answers · asked by thuong4187 1

carbonyl group
carboxyl group
carboxylic acid
organic acid
fatty acid
ester
formic acid
acetic acid


1. Another name for a carboxylic acid is a(n)_____________.

2. A carboxylic acid that has been extracted from animal fat is called a(n)____________________.

3. A(n)_____________ is identified by the presence of a carboxyl group.

2006-12-30 11:53:02 · 3 answers · asked by thuong4187 1

2006-12-30 11:51:00 · 2 answers · asked by daniel T 3

1The kinetic theory describes
a.how fast molecules move
b.the mass of molecules
c.the difference between temperature and pressure
d.how temperature and pressure affect matter


2.The temperature at which all molecular motion theoretically ceases is
a.273° C
b.0 K
c.–295° C
d.–273 K


3.Which of the following is defined as the amount of collisions between the molecules and the walls of their container?
a.temperature
b.mass
c.velocity
d.pressure


4.A hot day in July in the Utah valley typically reaches 40 degrees C. What is this in Kelvin?
a.233 K
b.313 K
c.273 K
d.400 K


5.You are most likely sitting in a room that is about 298 K. What is this temperature in Celsius?
a.298° C
b.0° C
c.25° C
d.75° C


6.As the temperature of a gas increases without the volume held constant, the average velocity of the molecules of gas will
a.increase
b.decrease
c.remain constant
d.vary randomly

2006-12-30 11:45:03 · 6 answers · asked by calebs_baby_girl05 1

The lattice energy of CaO(s) is -3,460 kilojoules per mole;
the lattice energy for K2O(s) is -2,240 kilojoules per mole. Account for this difference.

2006-12-30 11:36:05 · 1 answers · asked by Jacqueline 2

341.8328 J =____kJ

2006-12-30 10:02:38 · 4 answers · asked by silentcargo 3

Investigate how d concentration of a hydrogen peroxide solution affects d speed atwhich it decomposes to produce oxygen gas.

Can u help me with this I need info & don't know were 2 find it or can u give me a few tips. txs 4 u help

2006-12-30 09:34:00 · 2 answers · asked by well.theres.a.few 6

Doing my sci fair project iz due rly soon!!!
aaaaahhh!!!!
anyway i made 3 thermometers (homemade) one with alcohol & water together and another w/ just water & another w/ just alcohol.
i put them in a hot pan expectin the alcohol 1 to rise the most but the water rose out of the top (literally). i really confuzed!!!
help!!!
does water change volume when the temperature changes?

2006-12-30 09:26:17 · 10 answers · asked by racecar2daendofdastreet 1

2006-12-30 08:13:56 · 4 answers · asked by lalaland91 2

Seawater contains 3.4 g of salts for every liter of solution. Assuming that the solute consists entirely of NaCl (over 90% is), calculate the osmotic pressure of seawater at 23°C.

By using the formula osmotic pressure=(molarity)(temperature)(R), I got this...
1. M=mol/L=(3.4/58.4)/1 [because it says per liter]
2. T=23+273=296
3. MTR=1.41
...but the answer I got was wrong, so I tried multiplying the moles by .9 (thinking the 90% part was important), but the answer was still wrong. Any ideas?

2006-12-30 08:07:00 · 2 answers · asked by SDesign 1

Also, what makes the products form nuclear fission radioactive and how does one know???

2006-12-30 07:20:55 · 5 answers · asked by Sam L 2

2006-12-30 06:38:21 · 4 answers · asked by chweet16 1

CuSO4(s)--->Cu2+ with 2+ being on the top(aq)+SO2-4 with 2- on top while 4 on bottom(aq)

She placed 0.8 g of CuSO4(s) in a calorimeter iwth 43 g of water at an initial temperature of 18.3 degrees celcius. As the CuSO4(s) disslved in the water, the temperature rose to 20.2 degrees celcius.What value of enthalpy H can Teresa obtain from her data

How much heat will be tranferred when 0.54 mol sulfur reacts with 0.75 mol oxygen according to the following equation
2S(s)+3O2(g)--->2SO3(g) enthalpy change is -790 kJ
How many moles of SO3 will be produced?

I am really stuck on these two problems, would it be possible if you people could help me out on how to figure out this problem

2006-12-30 06:31:48 · 1 answers · asked by silentcargo 3

The temperature at sea level is 86oF. If we ascend to an altitude of 2,500 feet, what is the temperature at that height?

2006-12-30 06:19:33 · 2 answers · asked by nice too meet you. 4

2006-12-30 06:08:20 · 2 answers · asked by Master 2

i need the answers fast plz

2006-12-30 05:13:14 · 4 answers · asked by Anonymous

is 2-propanol organic or inorganic? why?
how many sigma bonds does it contain?
What are the intermolecular forces in it?
what is the molar mass?

2006-12-30 05:02:44 · 3 answers · asked by smitty♥ 2

I'm doing a WS for my HS chem class and it doesn't make sense.

2006-12-30 04:44:38 · 3 answers · asked by mbtafan 3

which gas will diffuse at the fastest rate under the same conditions of temperture and pressure?

1. F2
2.N2
3.H2
4.O2

--------------------------------------

what formula represents a tetrahedral molecule

a. HBr
b.CaCl2
c.CH4
d.B2

------------------------------

real gas behavior devitates from ideal has behavior because reall gas particles have

1. no volime and no attraction
2. volume and no attraction
3. no volume but some attract.
4. volume and some some attract.

2006-12-30 04:38:42 · 2 answers · asked by sibelly 1

Which of the following is a spontaneous process?
a) freezing of water @ 40 c
b) melting of ice @ -273 c
c)freezing of water @ -24 c
d) melting of ice @ -24 c

Which of the following correctly represents an exothermic reaction?
a) triangle H < 0
b) triangle H = 0
c) triangle H > 0
d) triangle H = 1

2006-12-30 04:33:41 · 6 answers · asked by queenpravato 1

2006-12-30 04:30:54 · 14 answers · asked by Anonymous

the amount of heat required to raise temperture os 1 gram of a sub. by 1 degree celius is called ?

heat vaporazation?
vapor pressure?
heat of fusion?
specific heat capaity?

2006-12-30 04:22:16 · 7 answers · asked by sibelly 1

A gas system has pressure, volume and moles of 1410 torr, 8.47 L and 0.346 moles, respectively. What is the temperature in Celsius?
279C
84C
127C
228C
110C

What is the relationship between the volume of a gas and the number of moles? What is the name of the law from which we derive this relationship?

The temperature at sea level is 86oF. If we ascend to an altitude of 2,500 feet, what is the temperature at that height?

100F
53F
98F
77F
64F
55F

Convert 750 kPa to atm.

70 atm
75.4 atm
7.403 atm (I got this one is this correct)?
6.983 atm

A sample of gas initially occupies 6.0 cubic meters at a pressure of 1.5 atm. The pressure is then expanded to 2.0 atm. The temperature remaining constant, what is the new volume of the gas?
(I got 18 is that correct)?

2006-12-30 03:04:56 · 1 answers · asked by Anonymous

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2006-12-30 02:22:35 · 4 answers · asked by lmmonisit 2