Chemistry - May 2007

an oxide of nitrogen is 26% nitrogen by mass. the molar mass of the oxide is approximately 105g/mol. what is the formula of the compound?

will someone please explain/show me how to do this one? i've been stuck on it for a while. thank you very much

2007-05-22 05:43:53 · 5 answers · asked by Anonymous

off of some ice? generally.

2007-05-22 05:42:35 · 3 answers · asked by Anonymous

can someone please show me step by step how to do these?

a) empirical formula: CH2; molar mass: 42g/mol
b) empirical formula: CH; molar mass: 78g/mol
c) empirical formula: NO2; molar mass: 92g/mol

thank you very much

2007-05-22 05:41:34 · 4 answers · asked by Anonymous

Balancing Equtaions?
Determine the product and then balance the following equations. Remember to use 2 for a subscript if you have a diatomic element by itslf.

So how would you do...

C16H30O16 + O2 =???

C3H60 + O2 =???

CaI2 + Cr2O=???

Al + HCl =???

CaF2 + K3(PO4) =???

2007-05-22 05:35:06 · 5 answers · asked by sanober h 4

Balancing Equtaions?
Determine the product and then balance the following equations. Remember to use 2 for a subscript if you have a diatomic element by itslf.

So how would you do...

C16H30O16 + O2 =???

C3H60 + O2 =???

CaI2 + Cr2O=???

Al + HCl =???

CaF2 + K3(PO4) =???

2007-05-22 05:26:16 · 2 answers · asked by sanober h 4

Balancing Equtaions?
Determine the product and then balance the following equations. Remember to use 2 for a subscript if you have a diatomic element by itslf.

So how would you do...

C16H30O16 + O2 =???

C3H60 + O2 =???

CaI2 + Cr2O=???

Al + HCl =???

CaF2 + K3(PO4) =???

2007-05-22 05:25:30 · 4 answers · asked by sanober h 4

2007-05-22 05:24:41 · 7 answers · asked by usavista 1

2) relate our answer to explain if it is possible for water to exist in 4 states?

2007-05-22 05:20:02 · 3 answers · asked by menimed1 1

2007-05-22 05:15:49 · 3 answers · asked by dana09 1

i need to figure out the sequnce chain and how to break it down to the simplest level if please help like now!!!

2007-05-22 05:15:40 · 3 answers · asked by lovely ladybug 2

At high concentrations of glycerol (90% volume for example), a glycerol-water solution tends to "suck" water vapor from atmosphere.
At low concentrations, the water evaporates.
Do you know what is the limit concentration between these two behaviours ? Or how to calculate it ?
Thanks

2007-05-22 05:11:40 · 2 answers · asked by pierre_mf 1

So what materials should I use to construct this. The best half reactions I can find are reduction of F2 and oxidation of Li. But at standard conditions that only gives me 5.92 Volts.
What might catalyze the reaction more? I might heat it, would that help. Or construct multiple batteries and pass them through the pickle at once.
Any ideas? Better half reactions?

2007-05-22 05:02:40 · 2 answers · asked by dorry 1

I know that U-235 and Pu-239 are the most commonly used isotopes in nuclear reactors and this sort of thing, but can -any- isotope be used, or are there only particular ones that will work?

2007-05-22 04:54:51 · 4 answers · asked by evenstar03 2

2007-05-22 04:51:30 · 4 answers · asked by evenstar03 2

2007-05-22 04:51:17 · 2 answers · asked by max 1

2007-05-22 04:40:01 · 4 answers · asked by xsbrokendreamspx 1

2007-05-22 04:33:05 · 1 answers · asked by Anonymous

I want to simulate organic and inorganic chemical reactions under various conditions.

2007-05-22 04:25:30 · 1 answers · asked by dtroupe2 2

I cant do this w/out knowing the mwt of the tablets (its not on the bottle or in the MSDS...). I cant just add tablets to acheive my pH cuz water has its own pH (which is probably around 6.8 too).

2007-05-22 03:43:54 · 1 answers · asked by MedTq367 6

Consider the following equation:
Caco3(s) + HCl(l) --> CaCl(s) + HCO3(l)
there is 500mL of Hydrochloric acid initially.
-calculate the mass of the calcium carbonate which would have reacted.
-calculate the initial concentration (molarity) of the HCl

2007-05-22 03:37:15 · 4 answers · asked by hiscageofstars 1

Need to show all appropriate calculations to estimate the pH at the equivalemce point for the titration of:
a) 0.1 M hydrocloric acid with 0.1 M sodium hydroxide
b) 0.1 M acetic acid with 0.1 M sodium hydroxide (hint: what is the concentration of the salt formed after mixing equal amount of these two reagents? you then need to determine the pH of the salt.)
c) 0.1 M ammonia with 0.1 M hydrochloric acid (hint: consider same hint as in b.)

You may need to look up pKa values.

THANK YOU!!!!!!

2007-05-22 03:20:22 · 2 answers · asked by miledi111 1

Please help! There are 3 Q:
1. From the definition of Ka for a weak acid, derive the following equation.
pH= pKa + log10 ([conjugate base]/[acid])
2. Based on the equation from question 1., what is the pH when 50% of an acetic acid was neutralised by sodium hydroxide? (call this pH50%). Similarly, what is the pH when there was a 55% neutralisation? (call this pH55%). What is the expected change between pH55% and pH50%?
3. What would be the final pH if 50 mL of water were added to 50mL of acetic acid/acetate buffer solution initially at pH 5.20? (consider the equation given in question 1.)

Could you please show the steps/workings as well!
THANK YOU!!!

2007-05-22 03:09:31 · 4 answers · asked by miledi111 1

2007-05-22 03:08:54 · 1 answers · asked by khsr1345 k 1

2007-05-22 03:03:13 · 11 answers · asked by isis s 1

2007-05-22 02:42:47 · 2 answers · asked by tim_childress 1

Also another question was... explain why electrons make up much of an atom's volume but not much of its mass.

2007-05-22 02:35:19 · 4 answers · asked by smitty_cent 1

2007-05-22 01:48:41 · 7 answers · asked by Anonymous

2007-05-22 01:34:52 · 2 answers · asked by brandix33x 1

(Select all that apply.)

proton donor
electron acceptor
proton acceptor
electron donor

2007-05-22 01:21:24 · 4 answers · asked by Jim H 1

2007-05-22 01:19:46 · 4 answers · asked by gingersnap704 1