Chemistry - November 2006

(HN3) (3=subscript)is a low boiling point liquid that is soluble in water in small quantities. It partially dissociates to form hydronium ions and azide ion (N3-)(3=subscript), with the pKa of 1.9 x 10-5 (5=subscript).

Calculate the pH of a solution of 0.724 g of HN3 in 400mL of water. Ignore any increase in volume due to small amount of HN3.

show work please.

2006-11-02 14:28:14 · 3 answers · asked by Anonymous

How can I tell if a compound is a metal or nonmetal? For example, Nitrate; is it a metal or nonmetal?

2006-11-02 14:21:17 · 6 answers · asked by Anonymous

think the ones who accerts the most wins

2006-11-02 14:19:27 · 10 answers · asked by Cateelk 3

please help!!

2006-11-02 14:13:04 · 4 answers · asked by meee 1

2006-11-02 13:51:52 · 2 answers · asked by last3member2002 1

2006-11-02 13:43:02 · 14 answers · asked by zhaine 2

Element X has 2 main isotopes, the wighted avg. mass of element X is found to be 26.73 amu. Isotopes A is found to have a mass of 23.4 amu and isotopes B is =27.9 amu. What are the precentage of the isotopes?

My Calculations:
23.4A+27.9B=26.73
A+B=1 A= 1-B
23.4(1-B)+27.9B=26.73
23.4+23.4B +27.9B=26.73
4.5B/4.5=3.3/4.5

B= 0.73 = 73%
A=1-B
A=1-0.73 = 0.27 = 27%

I copied this from the board, I understand it but my only problem is how I would figure that A=1-B? Also is there sites were I would find similar problems?

2006-11-02 13:37:19 · 2 answers · asked by Sophie S 1

A. It is caused by an unstable nucleus changing to become more stable.

B. It involves the release of particles and energy

C. the most common kinds of rays emitted are alpha rays, gamma rays and beta rays


True or False
When a radoactive atom emits an alpha particle, it is changed to an atom with a higher mass number and a lower atomic number

2006-11-02 13:30:10 · 2 answers · asked by cetinnovations 1

2006-11-02 13:19:30 · 2 answers · asked by Anonymous

2006-11-02 13:13:15 · 7 answers · asked by zhaine 2

What is the molarity of the sodium ion if the density of the seawater is 1.025 g/mL.

______M

2006-11-02 13:03:00 · 2 answers · asked by Poopz 2

(c) a solution in which [H+] is five times greater than [OH -]
_____ M

2006-11-02 13:01:56 · 1 answers · asked by Poopz 2

An electron in an atom is in the n=3 quantum level. List the possible values for L and m sub L that is can have

2006-11-02 12:57:47 · 2 answers · asked by dingdong 1

Is play-doh a solid, liquid, or a gas?

2006-11-02 12:57:33 · 13 answers · asked by kit kat 1

looking for detail and clear explaination

2006-11-02 12:56:47 · 1 answers · asked by tanny 1

2006-11-02 12:52:55 · 6 answers · asked by kelsey 2

Write the formula for each material correctly and then balance the equation.

2006-11-02 12:34:55 · 5 answers · asked by cassandra w 1

I am confused also on the conjugate base and acid and their pairs but I am most concerned with the equation. OTher than that, what about the equilibrium constant expression for this reaction?

2006-11-02 12:28:02 · 2 answers · asked by Adam 1

what are some toxic elements? elements only please.... and pleaSE HELP BECAUSE (sorry i didn't mean to do caps lock) the best of the first three or four ANSWERS to my questions (listed below) will automatically be chosen as best answer.
the info i need
1) a toxic element
if POSSIBLE:
2) type of element (nonmetallic, metal, metalliod)
3) atomic number
3) atomic mass
4) properties of that element,
ex. where found, natural state at room temperature, availablility on earth, natural existence on earth or not, why it is poisonous, and how it is poisonous, ETC... you know..
5) any other thing or anything else if possible
THANK YOU SOOO MJCH... please answer!!!!!! or email me, or whatever... or give me a link to a helpful site..

2006-11-02 12:20:57 · 6 answers · asked by GeTtHeExTrAcReDiTcUzIaM2mUcH4yOu 2

Calculate the density, g/cm3, of propane C3H8 at 95.0oC and 874 torr.

Remember, to enter an answer in exponential notation use e, example: 1.47e-8

HELP ME!!

2006-11-02 12:07:55 · 1 answers · asked by Anonymous

2006-11-02 12:06:39 · 2 answers · asked by Stevie B 2

2006-11-02 12:06:03 · 2 answers · asked by Anonymous

2006-11-02 12:05:10 · 1 answers · asked by Stevie B 2

From CuSO4*H20, The first weight was 1.57g, when heated, .57g of Suso4 was Left, How many Moles of Water(H20) was Lost?

1g/18g of H2O=.0556g/mol
.57g/(63.55*32.07*16*4) -->> .57/ 130435.104= 4.3699x10^-6

So now we divide both of them by teh lowest mole which for this equation is .0556g, right? But is the CuSO4 right? (The Mole)

Can someone check and answer this? Thank You!

2006-11-02 12:04:33 · 2 answers · asked by Anonymous

2006-11-02 12:04:12 · 5 answers · asked by Anonymous

2006-11-02 11:55:12 · 2 answers · asked by Leese 2

2006-11-02 11:51:19 · 3 answers · asked by Samina T 1

2006-11-02 11:49:25 · 1 answers · asked by Tracy B 1

2006-11-02 11:44:40 · 4 answers · asked by Leese 2

2006-11-02 11:40:14 · 2 answers · asked by Leese 2