Chemistry - February 2007

1 - How are poisonous oxides of nitrogen formed in a car engine?

2- Lead compounds are added to petrol to improve its efficiency why/how does this cause pollution problems?

3- How can pollution caused by lead additives in petrol be removed?

4- Carbon and carbon monoxide are pollutants formed by inefficient combustion of petrol - how could the efficiency be improved?

2007-02-06 07:03:20 · 6 answers · asked by Anonymous

I have two chem problems that I just cannot figure out. They are on Ideal Gas Law problems.
Please provide with me work (so i can see how to do it) and an answer.

1) 4.5g of magnesium is reacted with hydrochloric acid to produce hydrogen gas and a solution of magnesium chloride. What volume of gas would be produced at 2.5 atm and -8 degrees Celsius? PH20=2.5 mm Hg at -8 degrees Celsius

2) The density of a gas at room temperature (21 degrees Celcius) is 2.44 g/L. If the pressure of the gas is 0.178 atm what is the MM of the gas? (HINT: Does the density of a gas change based on the size of the sample?)


THANK YOU SOOO MUCH!

2007-02-06 07:00:23 · 2 answers · asked by Remy 5

2007-02-06 06:56:29 · 16 answers · asked by Anonymous

2007-02-06 06:48:35 · 2 answers · asked by dfgh d 1

Chemistry is so confusing to me..I can't seem to understand it.

2007-02-06 06:45:47 · 2 answers · asked by Anonymous

2007-02-06 06:25:36 · 2 answers · asked by Speed, I Am Speed 2

It has to be related to chemistry.....it can't be an experiment that can be considered a biological experiment or a psychological experiment.

2007-02-06 06:20:57 · 10 answers · asked by Anonymous

2007-02-06 06:08:18 · 2 answers · asked by chelsea l 1

2007-02-06 06:04:07 · 20 answers · asked by mrlovepantsuk67 1

2007-02-06 05:38:14 · 4 answers · asked by Liana W 1

I am trying to do a Project for my science teacher about Acids in Foods. One of the questions is How are acids used to make the food you selected? I have been looking for a web site that will tell me how acids get in the food I selected, which is Apples, but I can't find one! If anyone knows of a web site that deals with this, it would help a lot, because whenever I search for something on the internet, it comes up all heartburn remidies and apple recipies! I need help!

2007-02-06 05:34:17 · 2 answers · asked by kat2 2

I came across this question from the 2000 AP exam, and it seemed easy and so I answered it by now I don't know if it's right!!

H2S(g) 2 H2(g) + S2(g)
(a reverse reaction!)

When heated, hydrogen sulfide gas decomposes according to the equation above. A 3.40 g sample of H2S(g) is introduced into an
evacuated rigid 1.25 L container. The sealed container is heated to 483 K, and 3.72 ×10-2 mol of S2(g) is present at equilibrium.

(a) Calculate the equilibrium concentration, in mol L-1, of the following gases in the container at 483 K.
(i) H2(g)
(ii) H2S(g)

(b) Calculate the partial pressure of S2(g) in the container at equilibrium at 483 K.


Thank you!

2007-02-06 05:29:20 · 4 answers · asked by Anonymous

Cl2(g) ↔ 2Cl(g)

Cl(g) + CHCl3 → HCl(g) + CCl3 (slow)

CCl3 + Cl(g) → CCl4(g) (fast)


a) The overall rate law is equal to the rate law of the second step
as it appears above


b) k1[Cl2] = k-1[Cl]2


c) Cl(g) does not appear in the overall reaction


d) If this is a correct mechanism the observed law would be
Rate = k[Cl2]1/2[CHCl3]


thank you in advance!

2007-02-06 04:50:07 · 3 answers · asked by Anonymous

when an electron is displaced in a semiconductor, the hole that's left behind is
a. attracted to the negative terminal of the voltage source
b. incapable of carrying a charge
c. attracted to the anode of the voltage source
d. considered an impurity in the crystal

2007-02-06 04:27:23 · 2 answers · asked by Lynn D 1

2007-02-06 04:08:49 · 3 answers · asked by aly 1

I need help with this Chemistry molarity problem. Someone please help.

2007-02-06 04:08:05 · 4 answers · asked by Pat S 2

2007-02-06 04:06:20 · 4 answers · asked by dru 1

I need to find out what the contents are of the oxygen absorber packets you get in dried foods.

2007-02-06 04:04:00 · 4 answers · asked by Joy D 1

queria saber si hay alguna reacción entre el cobre y el etanol y si hay ....pues en que conducciones

2007-02-06 03:54:09 · 4 answers · asked by bish 1

What things that you would find in an average house react.. like vinigar and salt or.. pepper and cooking oil.. etc. etc..

2007-02-06 03:40:04 · 7 answers · asked by Anonymous

When 10.00g of barium is heated in air (reacts with oxygen gas), 15.00g BaO is produced. Calculate the percentage of oxygen in Bao. Use if desired: 2 Ba+O2 => 2BaO


** can someone show me how to work this step by step?** Thank you !

2007-02-06 03:31:18 · 4 answers · asked by mimi 1

I have done an experiment heating water using a spirit buner and i need to explain why combustion reactions are useful but i can't fine the info anywhere

2007-02-06 02:53:59 · 8 answers · asked by Crazy girl 5

2007-02-06 02:51:01 · 3 answers · asked by daniel e 1

2007-02-06 02:48:22 · 5 answers · asked by Jacqueline 1

2007-02-06 02:48:05 · 1 answers · asked by limun 2

why would sugar dissolve in water much faster then salt?

2007-02-06 02:27:15 · 7 answers · asked by cutie pie! 3

what types of intermolecular bonding is present in water methyl benzene and oleic acid. and how would these bonds explain the differences in time taken for the vortex to dissapear in each liquid?

2007-02-06 02:26:10 · 2 answers · asked by cutie pie! 3

2007-02-06 02:23:38 · 2 answers · asked by Anonymous

for each element in the following compound:

2Ca(NO3)2

2007-02-06 02:10:48 · 5 answers · asked by mimi 1

If a solution contains sulfate and chlorine anions, what preliminary test can be used to separate the two anions? Which anion is retained on the solution?

2007-02-06 01:46:16 · 3 answers · asked by cloudy 2