Chemistry - September 2007

In my solutions manual, a question is explained like this:
To react completely with NaOH, an acid must have a pKa at least 3 units smaller than the pKa of H2O (it's conjugate acid).

Is the 3 unit smaller thing true for all reactions that goes to 99.9% completion, or is it only specific for this particular reaction with NaOH?
Thanks!

2007-09-21 16:26:16 · 1 answers · asked by Yin H 2

its 2 ingridients i need for a project .
do u no how much it costs or wat it is and where they sell it??

2007-09-21 16:06:55 · 3 answers · asked by Anonymous

can anybody name a few non polar solvents?

2007-09-21 16:03:12 · 5 answers · asked by Anonymous

please explain step by step =)

2007-09-21 15:54:40 · 5 answers · asked by Anonymous

1st thing she put in was a few drops of food coloring
Then some high powered hydrogen peroxyde
Then they squirted in some dish soap
Finally they added a catalyst in a shot glass
I dont know what that was..they didnt say

It exploded in a seriously cool release of oxygen from the peroxide.
What was the catalyst?

2007-09-21 15:32:53 · 2 answers · asked by eddie9551 5

A combustion reaction involves the reaction of a substance with oxygen gas. The complete combustion of any hydrocarbon (binary compound of carbon and hydrogen) produces carbon dioxide and water as the only products. Octane is a hydrocarbon that is found in gasoline. Complete combustion of octane produces 8 liters of carbon dioxide for every 9 liters of water vapor (both measured at the same temperature and pressure). What is the ratio of carbon atoms to hydrogen atoms in a molecule of octane?

Ratio is incorrect. Write the balanced reaction equation and apply Avogadro’s hypothesis.

2007-09-21 14:50:23 · 3 answers · asked by Tamra 2

2007-09-21 14:50:06 · 4 answers · asked by uberifrit 2

meanings of the various table numbers given in the the text calculate how many neutrons there are in a phosphours atom.
a.15
b.16
c.31
d.none

2007-09-21 14:34:44 · 4 answers · asked by Leshell M 1

2007-09-21 12:07:16 · 1 answers · asked by dird 2

When the following reaction occurs
h_3po_4)(aq)+ca(oh)_2(aq)---->

what is the formula for the salt formed?

2007-09-21 12:01:30 · 2 answers · asked by stranger 1

Gas or liquid?
Or both?

2007-09-21 11:50:37 · 5 answers · asked by Anonymous

If you can, please include a source. THNX!

2007-09-21 11:06:46 · 3 answers · asked by lalala 3

A mixture known to contain AlBr3 and CaBr2 was analyzed by reaction with AgNo3 to precipitate all of the bromide ion as AgBr. If a 2.0143 g sample of the mixture yields 4.0034 g of AgBr, what is the weight percent of AlBr3 in the mixture?

2007-09-21 11:01:23 · 2 answers · asked by Kristin H 1

What is the chemical formula of the salt produced by neutralization of hydrobromic acid with Mg(OH)2?

and

What is the chemical formula of the salt produced by neutralization of sodium hydroxide with sulfuric acid?

2007-09-21 10:56:53 · 2 answers · asked by PiNk-PrInCeSs 3

(Type your answer using the format Pb3(PO4)2 for Pb3(PO4)2. If no precipitate forms, enter 'none'.)
(a) FeSO4 (aq) + KCl (aq)
(s)
(b) Al(NO3)3 (aq) + Ba(OH)2 (aq)
(s)
(c) CaCl2 (aq) + Na2SO4 (aq)
(s)
(d) K2S (aq) + Ni(NO3)2 (aq)
(s)

2007-09-21 10:50:00 · 3 answers · asked by Anonymous

Why is it that water holds the H- molecules down at an angle like a triangle while CO2 holds the O2 at 180 degrees from one another with the carbon in the middle??

2007-09-21 10:47:29 · 1 answers · asked by Anonymous

a.) HNO2
B.)HCN
c.) Ca(OH)2
d.) CH3CO2H

2007-09-21 10:36:12 · 3 answers · asked by ladypolars32 1

how many moles of CO2 can be produced from 2 moles of C3H8?

C2H8 + 5O2 -----> 3CO2 + 4H2O

2007-09-21 10:34:42 · 3 answers · asked by blueeyegreen 1

please explain

2007-09-21 10:10:45 · 3 answers · asked by PiNk-PrInCeSs 3

In my organic chem. class today, the prof. called a cyclohexane a hexane. That confused me. So I was wondering, what's the difference between hexanes and cyclohexanes?

2007-09-21 10:07:14 · 5 answers · asked by Mimi 1

Most of us agree that women wear perfumes and men wear cologne. But what is the difference in composition of the two? Does one differ markedly in chemical composition? And what is the difference in eau de toilette and parfum or parfume?

How would you go about manufacturing cologne or perfume? How would you make scented oils such as patchoulli?

2007-09-21 09:42:15 · 2 answers · asked by cafegroundzero 6

Fungal lactase, a blue protein found in wood-rotting fungi, is 0.340% Cu by mass. If a fungal laccase molecule contains 4 copper atoms, what is the molar mass of fungal lactase?

2007-09-21 09:26:50 · 0 answers · asked by s.weiss 1

I have three questions;

How many moles of atoms are in 10.81 grams of boron?

How many grams would 3 moles of boron weigh?

Ammonia molecules, NH3, have 1 nitrogen atom and 3 hydrogen atoms. How many grams would 1 mole of ammonia weigh?

2007-09-21 09:05:18 · 3 answers · asked by rwham 1

An examle of this would be how would you convert 12.4 g of sucrose (C12H22O11) into moles of sucrose?

2007-09-21 08:44:48 · 2 answers · asked by Robbie B 2

CaCN2 + 3H2O ----> CaCO3 + NH3

105.0 g CaCN2 and 78.0 g H2O are reacted. Assuming 100% efficiency, which reactant is excess andhowmuchis leftover? The molar mass of CaCN2 is 80.11 g/mol. The molar mass of CaCO3 is 100.09 g/mol.

2007-09-21 08:42:44 · 1 answers · asked by Jack L 1

The pipe drips at 155 mL/min. Express this in units of gallons/day.

2007-09-21 08:32:20 · 3 answers · asked by GinRum 1

i know that this seems like a dumb question, but i am supposed to do the following:

Write a balanced molecular equation, including physical states, that describes the
decomposition of magnesium hydroxide when heated in the crucible.

it looks balanced, but i just want to make sure as i am new at this. Thanks for the help.

Mg (OH)2(s) + heat ====> MgO(s) + H20(aq)

2007-09-21 08:27:35 · 3 answers · asked by john s 3

We had an element treasure hunt for physics today and I couldn't find some of the answers. Anyone know any of the answers?

2. Which element is commonly used in making light.
3. Which 3 elements would you find in a chest full of buried pirate treasure (f you're lucky)? ( I have gold and silver , but what is the 3rd?)
12. Which chemical symbol described the state of your head when your teacher asks you a question unexpectedly ?
15. identify the elements with the longest and shortest names.
16. Find the element that has the largest number of protons (It is not Uuo, UUh, or etc because those haven't been discovered).
Which element is named for the person most involved in our ability to blow things up?

Any help is greatly appreciated thanks!

2007-09-21 08:19:16 · 7 answers · asked by Anonymous

2007-09-21 07:26:59 · 4 answers · asked by AMii33 B33.. 1

n an equation, when the units are e.g. mol.dm-3/mol.dm-3. these units cancel out (1/1). So what would you say the units were, or just no units?

2007-09-21 07:26:54 · 3 answers · asked by harrycoates 2