Chemistry - December 2007

the answer is given 1.25 M but how do I get that?
thanks, studying for a Thursday test.

2007-12-04 17:54:01 · 2 answers · asked by Boo Radley 4

Acid rain can form from the combustion of nitrogen gas producing HNO3(aq) in a two-step process.
N2(g) + 2O2(g) → 2NO2(g)
3NO2(g) + H2O(g) → 2HNO3(aq) + NO(g)

a. A car burns 420. g of N2 according to the above equations. Howmany grams of HNO3 will be produced?

b. For the above reactions to occur, O2 must be in excess in the first step. What is the minimum amount of O2 needed in grams?

c. What volume does the amount of O2 in part b occupy if its density
is 1.4 g/L?


I don't get it. If you can help, thanks a ton !
much help appreciated ! :D

2007-12-04 17:17:01 · 1 answers · asked by ♥ ♥ ♥ 3

Any help would be greatly appreciated.
1. Write the pH of the following solutions:
a. [HNO3=1.0 x 10 -3M
b. [H3O+]=2.5 x 10 -4M
c. 1.0 x 10 -2M KOH
d. [OH-]=0.00037M

2. Hydrocyanic acid, HCN, reacts with water to form a solution containing CN- and hydronium ion. Write the chemical equation to show the reaction of hydrocyanic acid with water. List the formula of the conjugate base of HCN; List the chemical formula of each acid in the equation. Then write the Ka expression for this reaction.

3. The value of the acid ionization constant, Ka, for HCN is 4.4 x 10 -10. What is the concentration of H3O+ in a 1.65M solution of hydrocyanic acid? Show set-up.

4. What is the pH of the 1.65M HCN solution?
Thanks in advance!!

2007-12-04 17:16:45 · 1 answers · asked by ortegaphoto 1

Could you please tell me some important facts and information about the element silver (Ag). Im doing a report and i need some good information. I researched a lot on the web but i couldnt find a site with a lot of good information.

2007-12-04 17:12:34 · 3 answers · asked by Tato 2

A solution is made by adding 54.06g of glucose (C6H12O6) to 250.0g of water. The final volume of the solution is 291 mL. (molar mass of glucose = 180.2 g/mol)...

fond the percent by weight of glucose in the solution...

2007-12-04 17:08:10 · 2 answers · asked by millie1615 1

the mass of 0.25g of Zn.
moles of the 0.25g Zn.
volume of 10mL of 6M HCl

2007-12-04 14:26:32 · 2 answers · asked by Anonymous

This question is a "conceptual question" in my chem textbook, in the Solutions chapter. I suppose it has something to do with the acidic properties in vinegar.... but what of the salt? Does it wilt because it needs -OH molecules from the water in the salad?

Thanks for your ideas!

2007-12-04 14:24:25 · 3 answers · asked by Anonymous

Calculate the number of molecules exhaled in each breath at body temperature, 37 degrees celcius and 1.0 atm.

2007-12-04 14:21:22 · 2 answers · asked by flo_town02 1

could it be because of the pressure change from the temperature in our house being colder in the morning, so less force was being exerted on the lid, and later it was easier because it was warmer and there was more force on the lid?

i wanna know if my sister is stronger than us! we both work out just as much as she does!

thanks~

2007-12-04 14:19:44 · 13 answers · asked by Eileen 1

Can anyone give me the international color used for medical tanks such as oxygen tank...,carbon dioxide tank??? (In the Hospitals)

2007-12-04 14:13:11 · 4 answers · asked by Jarold A 2

2007-12-04 13:55:54 · 1 answers · asked by Anonymous

1.Assuming that gasoline is C8H18 and has a density of 0.703 g/ml, how many liters of CO2 will be produced from the consumption of 2.5 gallons of gasoline at standard condtions ?

any help would be greatly appreciated!

2007-12-04 13:52:40 · 2 answers · asked by matt b 1

So I am supposed to write an experimental procedure for determining the volume of gas generated when 6 grams of a TUMS antacid table is added to 30mLs of 1M acetic acid. Apparently the method of measuring gas volume by water displacement with a buret will not work for this experiment because the experiment may generate too much gas. I am then supposed to indicate what needs to be known exactly. Any idea what this means? Thanks.

2007-12-04 13:36:44 · 2 answers · asked by David R 1

Cis-Platin is a chemotherapy drug that has the formula PtCl2(NH3)2. If you have 402.00 grams of cis-platin, how many grams of nitrogen would it contain? Enter your answer in scientific notation. For example 3.14E-6.

i don't understand how to go around doing that either
help please

2007-12-04 12:55:01 · 4 answers · asked by DDTHAPPINESS 5

A silver bar of length 30 cm and cross sectional area 1.0 cm^2 is used to transfer heat from a 100 degrees C reservoir to a 0 degree C block of ice. How much ice is melted per second? (For silver, k = 427 (SI units). For ice, Lf = 334 000 J/kg.)

2007-12-04 12:48:45 · 1 answers · asked by Mark N 1

What are Radioactive and Synthetic Elements?

(characterists)

2007-12-04 12:40:22 · 1 answers · asked by Kriss 2

How many fluorine atoms are necessary in the Lewis dot structure of the ionic compound containing calcium and fluorine?

How many lone pairs will be on the carbon atom in CBr4?

Only answer if you are positive!!!

2007-12-04 12:37:02 · 2 answers · asked by Emily 4

Science question......

2007-12-04 11:38:45 · 2 answers · asked by Anonymous

why are masses different from a triple beam balance and the electronic balance?

thanks!

2007-12-04 11:10:08 · 1 answers · asked by Anonymous

Assuming that gasoline is C8H18 and has a density of 0.703 g/ml

2007-12-04 11:00:40 · 2 answers · asked by tibsy2007 2

How many moles of O2 are present in 44.8L of O2 at STP?

How many moles of CO2 are present in 4.00L of CO2 gas at STP?

What volume in liters is occupied by 2.5 moles on N2 at STP?

2007-12-04 09:40:53 · 4 answers · asked by Anonymous

What are Neils Bohr's theoretical connections between the energy level transitions of an electron and the specific color of a photon in the hydrogen line spectrum?

Please explain the advantages and disadvantages in the modern quantum mechanical model over the Bohr model. Use the following concepts in your answer: Heisenberg Uncertainty Principle, quantum numbers, orbital, sublevel, Hund's Rule, Pauli Exclusion Principle.

There is a greater variation between the properties (both chemical and physical) of the first and second of a group or family in the periodic table than between the properties of the second and third members of the group. Consider as examples either the group containing nitrogen or the one containing oxygen. Select three properties and discuss the variation of these properties to illustrate the generalization expressed in the first sentence of the question.

2007-12-04 09:33:45 · 2 answers · asked by Bollywood Masti 4

given: Butane (C4H10) has a heat of vaporization of 22.44 kJ/mol and a normal boiling point of -0.4 degrees celsius. A 250 mL sealed flask contains 0.55g of butane at - 22 degrees celsius.
How much butane is present as a liquid?
I got 0.25g

so I can't do the next question...
If the butane is warmed to 25 C , how much is present as a liquid?

2007-12-04 08:30:39 · 3 answers · asked by Pooh 4

The human body obtains 970 KJ of energy from a candy bar.
If this energy were used to vaporize water at 100.0 C , how much water (in liters) could be vaporized? (Assume the density of water is 1.00g/mL .)

2007-12-04 08:26:51 · 1 answers · asked by Pooh 4

HI
CO
CCl4
NaCl
N2

2007-12-04 05:36:50 · 3 answers · asked by Anonymous

2007-12-04 05:35:05 · 2 answers · asked by Chs_8_Hoopster 2

when zinc in refined by electrolysis, the following reaction at the cathode is:

zn2(aq)+ +2e- ---->zn(s)

a competing reaction which lowers the yield is the formation of hydrogen gas

2H+ (aq) + 2e- ------>H2(g)

If 91.5 % of the current flowing results in zinc being deposited, while 8.5% produces hydrogen gas, how many liters of H2 (g), measured at STP, form per kg of zinc?

2007-12-04 05:14:09 · 3 answers · asked by skoolgrl217 2

I did a lab and the sheet has 3 problems:
I need someone to look over two of them and explain the third one.

Write a balanced equation for the reaction that took place:
I got - CaCl2 + Na2CO3 ----> CaCO3 + 2NaCl

What kind of reaction took place:
Double Replacement?

And now it wants a Net Ionic Equation?
How would I write that?

2007-12-04 05:00:00 · 6 answers · asked by Anonymous

1. Explain how sodium hydroxide solution and hydrogen are produced by the electrolysis of sodium chloride.
2. when copper sulphate solution is electrolysed using carbon electrodes, the electrolyte becomes acidic after some time. why?
3/ Aluminimium is obtained by the electrolysis of motlen aluminium oxide. Name the anode and the cathode and the electrolyte using in the method. write the electrode reaction alos.
please help me, i dont understand the questions!!! thanks who ever helps!

2007-12-04 04:30:28 · 1 answers · asked by unknown 1

2007-12-04 04:22:59 · 5 answers · asked by Pastinie 3