Chemistry - September 2007

2) What mass of Cu(NO3)2 is present in 276 mL of a 0.40 M solution? (Enter unit as g.)
3) What mass of KNO3 is needed to add to a 500 mL volumetric flask to produce a solution that is 0.40 M? (Enter unit as g.)
4) What is the molarity of a solution produced by dissolving 26 g of KI in a 1000 mL volumetric flask?(Enter unit as M.)

2007-09-30 23:32:27 · 2 answers · asked by KC 1

and please tell me the types of acid and bases..
example:
grape:
Please give me as many as you can!

2007-09-30 23:17:59 · 2 answers · asked by Anonymous

Fluorite, a mineral of calcium, is a compound of the metal with fluorine. Analysis shows that a 2.76 g sample of fluorite contains 1.49 g calcium. Calculate the following:

(a) mass (in g) of fluorine in the sample ___

(b) mass fraction of calcium and fluorine in fluorite

(c) mass percent of calcium and fluorine in fluorite

(Please explain it to a beginner step by step so that I can figure it out on my test tomorrow... first to answer correct and thorough gets best answer... thanks so much!)

2007-09-30 21:20:42 · 3 answers · asked by Anniepannie06 2

If not,what are they? can someone tell me more about them?

2007-09-30 20:58:04 · 8 answers · asked by Anonymous

2007-09-30 18:45:10 · 3 answers · asked by Brandon 1

2007-09-30 18:25:17 · 4 answers · asked by Anonymous

A compound has the empirical formula CHCl. A 256-mL flask, at 373 K and 750 torr, contains 0.800 g of the gaseous compound. Give the molecular formula.

256 mL = .256 L, 373 K, 750/760 = .987 atm

PV = nRT = (.987)(.256) = n(.08206)(373) ---> n = .008 mols

CHCl, MW = 48.648 g/mol ---> (.80g)/(48.648 g/mol) = .016

(.016)/(.008) = 20

C20H20Cl20 = Molecular Formula.

Is this right?

2007-09-30 18:13:45 · 2 answers · asked by the Jam 2

hi have the equation AuxOy which makes gold oxide. How do i find out how much x there is and how much y there is? i know that there is 89.15% Au in the equation.

2007-09-30 18:07:39 · 1 answers · asked by Anonymous

Okay I don't get this, if someone answers my questions I'll give them 10 points. I get everything except the sulphur oxide. I know they are covalent bonds, but why doesn't oxide have 'mono'? Would the sulphur oxide be S2O2, then reducing it be SO, or S2O, I'm confused. I don't get the covalent bonding, would the diatomic apply to covalent bonds? For example if both elements are negatives, such as sulphur and oxygen, when you combine them would oxygen have a 2 because its diatomic but then shouldn't it say dioxide why does it only say sulphur oxide? Okay so would the UNbalance equation be HS + O2 = H2O + SO?

2007-09-30 17:50:33 · 5 answers · asked by Jenna 1

How would you do this?

If the only two naturally occurring isotopes of chlorine, C1-35 and C1-37, have relative atomic masses of 34.969u and 36.966u respectively, what must be the approximate abundance of each in nature if the average atomic mass of chlorine is 35.453u?

2007-09-30 17:45:24 · 1 answers · asked by Pig 6

Cl2
SO2
HCCH
CS2
CCl4

2007-09-30 17:45:12 · 2 answers · asked by Anonymous

The question is: Balance the redox reaction which occurs in acid solution.

Fe2+(aq) + Cr2O72-(aq)-->Fe3+(aq)+Cr3+(aq)

If you can help me with this I'll gladly choose your answer as the best one.

2007-09-30 17:19:49 · 3 answers · asked by Craig S 2

2007-09-30 16:39:12 · 3 answers · asked by Merbit 2

Why does an increase in temperature increase the rate of exothermic as well as endothermic reactions?

2007-09-30 16:32:34 · 1 answers · asked by Anonymous

I ripped out the answer pages at the back of the book so I wouldn't be tempted to look at the answers and now I've lost them!! Any help would be appreciated, I really need to clarify if my answers are correct!

2007-09-30 16:23:17 · 1 answers · asked by Anonymous

Of the following, a 0.1M aqueous solution of _________ will have the lowest freezing point, and why?
A) Al(NO3)3
B) K2CrO4
C) Na2SO4
D) NaCl
E) sucrose

2007-09-30 16:21:34 · 1 answers · asked by Anonymous

All I know is the The Iron Triad is made up of iron, cobalt, and nickel.

2007-09-30 16:14:35 · 1 answers · asked by future Mrs. Nick Jonas :) 1

what does it mean.... between people and friends just not relationships

2007-09-30 16:12:04 · 1 answers · asked by Anonymous

A solution containing 296.6 g of Mg(NO3)2 per liter has a density of 1.114 g/mL. What is the molarity of the solution?

2007-09-30 16:07:57 · 1 answers · asked by Anonymous

2007-09-30 16:00:28 · 4 answers · asked by Anonymous

2007-09-30 15:46:43 · 1 answers · asked by some guy 1

what type of work was done by both newton and boyle, I am having a large amout of trouble finding understandable information on this.

2007-09-30 15:29:33 · 1 answers · asked by Olivia 2

If so.. is there a name for it or something?

2007-09-30 15:01:47 · 2 answers · asked by ehgirl 2

2007-09-30 14:56:00 · 3 answers · asked by future Mrs. Nick Jonas :) 1

cyclohexae (C6H12) freezes at 6.55 degrees C. A solutionof 1.67 g of carbon disulfide (CS2) in 50.0g of cyclohexane freezes at -2.25 degrees C. What is the freezing point depression constant for cyclohexane??

2007-09-30 14:48:14 · 1 answers · asked by Anonymous

2007-09-30 14:44:44 · 4 answers · asked by Shushan A 2

Mi brother is a chemist and gave me a bag of this......? He said to me do not mix with water.........and what do you do ....?mix with water! Ruined all my brickwork! Was he right or was it somethig ELSE?

2007-09-30 14:39:28 · 6 answers · asked by christopher831@btinternet.com 1

What is the oxidation number of Mn in the compound:

KMnO4

I came up with 7, but the answer key says I am wrong

2007-09-30 14:36:37 · 3 answers · asked by Anonymous

If you burn a piece of magnesium, the mass of the piece increases. Why?

2007-09-30 14:31:46 · 6 answers · asked by Anonymous

2007-09-30 14:30:42 · 8 answers · asked by tanman 1