Chemistry - December 2007

the question asks us to calculate (i) the number of moles of CO2 produced.. (ii) the no. of moles of water produced.. (iii) determine the molecular formula of X..

how do u do this? u don't have to give the answer.. just guide and tell me the steps involved..

2007-12-21 12:35:02 · 2 answers · asked by Anonymous

54.9 g of solid aluminum hydroxide, Al(OH)3, is neutralized with 91.9 g of sulfuric acid, H2SO4.

a. Write a balanced equation of the reaction?

b. Which one is the limiting reagent?

c. How many grams of aluminum sulfate will be produced?

d. How much of the excess reagent(in grams) is left at the end of the reaction?

2007-12-21 12:34:40 · 1 answers · asked by Charlie W 1

making a large batch of acid/base indicator using canned blackberries- about a pint's worth, unknown molarity or composition

"juice" of this canned is what I used for indicator, I have so far filtered it and diluted it a little

my problem: when packaged some sort of sweater has been added, "light syrup". I'm guessing its either corn syrup or plain old sugar. I need to get rid of it without wasting much of the actual solution or spending much money. Any suggestions?

2007-12-21 11:38:16 · 1 answers · asked by Flaming Pope 4

in order to stop students from cheating? i want to know so that i can get with the program if thats whats going on.

2007-12-21 09:42:25 · 4 answers · asked by Anonymous

2007-12-21 08:36:50 · 1 answers · asked by safa s 1

A 20.0 % (w/w) solution of glucose (C6H12O6, molar mass = 180.16 g/mol) in water has a density of 1.0395 g/mL. What is its molarity and molality

2007-12-21 07:19:02 · 0 answers · asked by Poeteress 1

What is the enthalpy change when 5.2 mol of lead(II) oxide reacts with excess sulfur dioxide

2007-12-21 07:11:55 · 1 answers · asked by amanda R 1

2007-12-21 06:44:10 · 7 answers · asked by Anonymous

Electrons generally flow from a point of deficiency to a point of excess in an electric current.

2007-12-21 06:15:18 · 5 answers · asked by flabbergasted 1

2007-12-21 05:32:02 · 15 answers · asked by ben t 3

my stupid friend thinks that its not
prove to her it is

2007-12-21 05:09:04 · 21 answers · asked by K-jn 4

Problem #1:
Aluminum oxide is formed from the reaction of metallic aluminum with oxygen gas. How many moles of Aluminum are needed to form 3.4 moles of Aluminum oxide?
Hint: This is a simple ratio problem. Just use the molar ratio from the balanced equation. This was covered in 5.09. Mass is not involved.

Problem #2:
Determine the number of grams of NH3 produced by the reaction of 3.5g of hydrogen gas with sufficient nitrogen gas. (Check for diatomic elements).
Can U Show me how 2 balence and how 2 and what 2 cancel.
PLEASE I NEED YOUR HELP!

2007-12-21 03:54:07 · 6 answers · asked by Monica Yuzuma 1

Please could you help me work out what mass would be needed, I got the answer as 84.5. But im unsure if its correct!

Equation: 2NaN3(s) ---------- 2Na(s) + 3N2(g)

What mass of sodium azide (2NaN3) would be needed to liberate 48dm3 of nitrogen? (Molar volume of gas is 24dm3mol-1)

2007-12-21 03:30:38 · 1 answers · asked by Anonymous

1.NaCl
2.MgF2
3.CCl4
5.C6H6

2007-12-21 03:10:03 · 1 answers · asked by Kelly 1

okay so......

I need to find:

1) the mass of 350.0 L of Nitrogen, N2 at STP

2) What is the mass of 43.231 moles of Cu

3) How many moles are in 3.56 x 10^32 of N2

4) How many moles are in 4.38 x 10^42 atoms of zinc

5) how many atoms are in 2.41 x 10^24 molecules of water (H2O)

6) how many moles are in 403 grams of SO4

THANK YOU

-Colorado Boy

2007-12-21 02:55:58 · 4 answers · asked by Anonymous

I am doing a science fair project on rusting nails. I am going to put 1 nail in a jar containing water, salt water, bleach and vinigar to see which liquid will make the nail rust faster. My question is, should I put the lid on the jars or just leave them open?

2007-12-21 02:53:56 · 4 answers · asked by jaydkast 4

2007-12-21 02:44:21 · 8 answers · asked by Anonymous

i know that it's rarely ever pure MDMA and that it's often cut with ephedrine and amphetamines, but is heroin really ever present? i've never done E and never will, but my husband and I were discussing it last night and neither of us know. I tried getting on Erowid.org, but the site appears to be down and I didn't find much info elswhere.

2007-12-21 02:40:38 · 3 answers · asked by SpiderDijonRevisted 3

and what about room temperature water?

2007-12-21 02:25:55 · 7 answers · asked by patrick m 2

No number is writeen in writing a formula when the valence numbers of both the metals and nonmetal in a compound are 1.


If you do know the answer, could you please explain this to me. I have absolutely no idea what it means?

2007-12-21 02:24:41 · 6 answers · asked by Kattie 1

Me and my friends bought Mentos and Coke, but they said that they got news that someone died when these two were taken. And they said that there will be a reaction when any mint is taken with acid. I wonder if this is true.

2007-12-21 01:48:24 · 5 answers · asked by Keybearer 2

If I wanted to extract a compound which was dissolved in a mixture that contained both water and ethanol, what would be the best solvent to use? Am I correct in assuming that I need something which is not miscible with either water or ethanol? And might this be a problem as ethanol is miscible with polar and non-polar solvents?

Thanks

2007-12-21 00:57:36 · 2 answers · asked by Anonymous

Can anyone help me figure out how to find the formula for this hydrate?

3.71 g Na2CO3, 6.29 g H2O

Thanks!

2007-12-20 19:53:32 · 2 answers · asked by Anonymous

2007-12-20 19:42:22 · 2 answers · asked by Anonymous

What would the quantum numbers for the d electrons in Tc and Tc+7 be? Also. How many unpaired electrons in the atom. In the ion? How many p electrons in the atom? In the ion? Help please. D=

2007-12-20 17:36:00 · 1 answers · asked by Brookeachu. 2

....that ...They can extract metal from ore. Metallurgical procedure are not very easy. What helped them distinguish that some minerals are ore and some are stones.
We find ores deep down the surface. By no means ancient people could have dug so deep. How did they got knowledge that iron can be extracted from hematite. Similarly copper, bronze from their ores etc.etc.
Were they damm genius gifted with mind blowing intuitive powers or god appeared in there dreams saying ' O man goeth there, diggeth it, melteth it in absence of air and geteth iron'.
How did it popped in their brain that ores can give them metal.
Thank you for your time.

2007-12-20 17:03:47 · 3 answers · asked by Fantail Flycatcher 3

I would appreciate someone explaining the steps needed to solve this so I can do it myself. I don't just want an answer. Thanks.

A clean burning engine will emit about 5.5 lbs of carbon in the form of CO2 for every gallon of gas it consumes. Illistrate this statement to be mathmatically correct by using the following information:
a) one of the main components of gasoline is octane (C8H18) with a density of 0.692 g/mL. 1.00 gallon has the same volume as 3,790.00 ml. 454.00 grams = 1.00 lb.
b) another component of gasoline is toluene (C7H8) with a density of 0.867 g/mL.

2007-12-20 15:36:47 · 3 answers · asked by Anonymous

...in other words, a person who took chemistry in college for a semester and who knows a good bit about chemistry and reads all the books they can find but is not a graduate of a university or a true chemist in the professional sense of the word. Is it legal for them to set up a small lab at their residence in the U.S. for research and to conduct experiments? I'm not talking about an illegal drug manufacturing lab or anything illegal like that. I'm talking about a legitimate chemistry lab for experimental and research purposes. A place with the resources to further an insatiable interest in chemistry.

2007-12-20 15:10:35 · 2 answers · asked by Felix Arcanus 5

1. The number of which atomic particle determines the identity of an element? (3 choices)

proton
neutron
electron

2. Which of the following has almost no mass? (3 choices)
proton
neutron
electron

3. Which of the following orbits the nucleus? (3 choices)
proton
neutron
electron

4. Metals are: (3 choices)
poor conductors.
brittle.
malleable.

5.The principal quantum number indicates the: (3 choices)
pair of electrons.
main energy level.
subshells.

6. The outer energy level of a noble gas is: (3 choices)
empty.
filled.
half-filled.

7. The modern periodic law states that properties of elements are functions of their: (3 choices)
atomic numbers.
atomic masses.
electrons.


**don't worry more questions to come :)

2007-12-20 14:15:47 · 7 answers · asked by Anonymous

'coldest fire'

2007-12-20 14:14:25 · 2 answers · asked by Thomas E 7