Chemistry - March 2007

2007-03-27 08:21:59 · 1 answers · asked by Anonymous

2007-03-27 08:13:35 · 2 answers · asked by yummy_applesauce 2

If a gas is compressed from 5 L to 1 L and the temperature remains constant, what happens to the pressure

1.The final pressure is 5 times the original pressure.

2.The final pressure is the same as the original pressure + 5 atm.

3. The pressure remains constant.

4. The final pressure is 1/5 of the original pressure.

2007-03-27 08:07:04 · 2 answers · asked by chemrob3 1

2007-03-27 08:05:09 · 5 answers · asked by Lavonte G 1

2007-03-27 08:02:23 · 2 answers · asked by Lavonte G 1

2007-03-27 08:01:01 · 7 answers · asked by Lavonte G 1

kNOWLEDGE

2007-03-27 07:58:17 · 5 answers · asked by Lavonte G 1

2007-03-27 07:37:06 · 2 answers · asked by Anonymous

Could someone please explain, in reasonably simple terms, what is the difference between the methods listed above. Can they all be used for quantitative analysis of foods? I've tried looking them up on the internet but am getting a bit confused. What about Kjeldahl analysis? Can this be used to determine protein in food samples?

2007-03-27 07:36:41 · 4 answers · asked by Derek C 1

respiration committed some errors shown in the figure
What changes should be made in the set up to get the desired results?
1) KoH solution should be taken in the small test tube inside the flask and
germinating seeds in the beaker.
2) Water should be taken in the beaker and KoH solution in the flask.
3) KoH solution should be taken in the small test tube inside the flask and
water should be taken in the beaker
4) Water should be taken in the flask and KoH solution in the small test tube.

2007-03-27 07:34:31 · 1 answers · asked by salilsuneja 1

....i need to know for my chemistry homework
i was supposed to research it but it comes up with things about coke when i google it!
can anyone please help me?

thanks in advance
xxx

2007-03-27 07:32:49 · 3 answers · asked by twinkle star 3

True or False
1. Nonpolar covalent bonds have a low ionic character.
2. Atoms tend to form bonds so that each atom has 12 electrons in its highest energy level.
3. Long covalent bonds have more energy than short covalent bonds.
4. Multiple covalent bonds usually have less energy than single covalent bonds.
5. A hydrogen atom is attracted to an unshared pair of electrons with London forces.
6. Nonmetals are usually more electronegative than metals.
7. When drawing a Lewis structure, the most electronegative atom is placed in the center (except for hydrogen).
8. Lattice energy is the energy released when an ionic crystal forms. It is greater than the energy needed to break the crystal apart.

2007-03-27 07:31:12 · 2 answers · asked by Domino 1

I have 50 mL of HCl, with a pH of 1. I need to know what the Molarity is.

2007-03-27 07:14:43 · 2 answers · asked by ur_sorrow_is_so_sweet 1

For methanol, ethanol, propanol. butanol, pentanol and hexanol i need to find the theoretical energy transfer if they were burned in air (oxygen).

This requires balancing the equations which i have already done but when it comes to the actual calculations, my results have no pattern and aren't all negative numbers (as they should be as they are exothermic.) I know they are wrong but i can't see where I am making the mistakes. If someone could explain, do one example for me, i would be so greatful, here's what you need to know:

The equation: Alcohol + Oxygen ---> Carbon dioxide + Water
Bond values (Kj/mol)
H-C - 413
C-C - 347
O-C - 336
O=O - 498
C=O - 805
O-H - 464

eg. balanced: 2CH3OH + 3O2 ---> 2CO2 + 4H20
for all equations:
O2 = double bond
CO2 = C=0 double bond x2
all other compounds/elements contain single bonds

Thanks so much to anyone who can help, i have been struggling with this for so long now.

2007-03-27 07:12:02 · 1 answers · asked by Snap-crackle-pop 1

2007-03-27 07:02:12 · 5 answers · asked by Arjit K 1

i have 50 mL of HCl for a stomach simulation, but i need to know what the molarity of the HCl is if pH is 1.

2007-03-27 06:54:45 · 3 answers · asked by Anonymous

3. What two things in the chemical formula of a compound, would indicate that you might be dealing with an acid?

2007-03-27 06:51:07 · 1 answers · asked by Anonymous

Which of the following are reducing agents ?


a) H2


b) Cl2


c) Fe


d) Cr2O72-


e) C

2007-03-27 06:46:38 · 2 answers · asked by sunyrob 1

what are CFC's? all i know is that its something to do with crude oil/petroleum/oil but im not sure wat it is. please help

2007-03-27 06:40:21 · 5 answers · asked by Anonymous

2007-03-27 06:40:18 · 8 answers · asked by mimi 1

HA(aq) <====> H^+ (aq) + A^- (aq). HA is a weak acid in solution. A- is the conjugate base. Suppose salt is added to the aqueous solution to yield an initial concentration for A- of [A-]=0.3 M. 1.00 M of HA is then added. K for the reaction = 1.0 x 10^10. whic of the following statements is incorrect.

1. At equilibrium the solution is acidic.

2. the final concentration of H+ is [H+]= 3.3 x10^-10 mol/L

3. The pH for the equilibrium solution is 9.5.

4. the final concentration of HA is approx. 1.00 M

2007-03-27 06:30:47 · 1 answers · asked by rnjes21 2

By the way, are vitamins considered substances?

2007-03-27 06:27:20 · 3 answers · asked by Anonymous

please can you help me write balanced equations to illustrate:
(i) Electrophilic addition
(ii) Nucleophilic substition
(iii) Free-redical substitution

Thank you!

2007-03-27 06:22:05 · 1 answers · asked by Anonymous

1.Each partial pressure is the total pressure that one component exerts on the system.

2.The partial pressures are the individual contributions from each gas component of the system. When they are combined, they equal the total pressure of the system at equilibrium.

3.If you are given the Kp value and the total pressure for a system, you can calculate the partial pressures of each gas component.

4. The partial pressure of a gas is considered to be unity, or 1

2007-03-27 06:20:52 · 1 answers · asked by rnjes21 2

to form 2 mols of H2o. The normality of H2so4 or NaOH in this case is 2.

Now if I'm getting an acid salt(NaHSO4) what will be the normality?

2007-03-27 06:02:04 · 1 answers · asked by tut_einstein 2

How hard is BioChemistry? (BS degree)? Whats the harest?

2007-03-27 05:57:24 · 1 answers · asked by b_ney26 3

please i need help!!

2007-03-27 05:47:34 · 4 answers · asked by Anonymous

A chemist is studying the properties of a gas occupying a bulb connected to a U-tube manometer, the other end of which is open to the air. The gas in the bulb is in contact with a solid chemical, with which it may be reacting. The observation is made that the level of the mercury in the U-tube on the side of the bulb is gradually falling over time. Which of the following cannot be a potential cause for this?

A. The temperature of the gas inside the bulb is increasing.
B. A reaction is occurring inside the bulb that is increasing the number of moles of gas.
C. The prevailing atmospheric pressure is falling.
D. The gas is reacting with the solid to produce one mole of product gas for every mole of reactant gas consumed. However, the product gas has a higher molar mass.
E. The solid is subliming (evaporating).

2007-03-27 05:32:49 · 1 answers · asked by Anonymous

I'm working on a case where a person is accusing a neighbor of throwing "muritic" acid on his vehicle. I don't know what this is, and can't find any references to muritic acid on the net, however I found "muriatic" and "muratic". I'm a humble cop and not familiar with chemisty! Why would someone have either of these around his house? Are there particular jobs or hobbies that would use these?

2007-03-27 05:22:22 · 2 answers · asked by Anonymous

2007-03-27 05:21:47 · 4 answers · asked by lemarcus walker 1