Chemistry - March 2007

If you are forming a compound using a Grignard reagent and you are considering steric effects, which must be bulkier: the Grignard reagent, or the molecule to which it is being added?

Example:You want to form a tertiary alcohol by using a Grignard reagent and a ketone. Should the reagents used be (the C in parentheses is also double bonded to an O):

CH3CH2(C)CH3 + CH2CH2MgBr
and then add H3O+
(Such that the Grignard reagent is the more sterically hindered one)

OR

CH3CH2(C)CH2CH3 + CH3MgBr, then add H3O+
(Such that the Grignard is the less sterically hindered reagent)
?

Thanks so much!!

2007-03-19 15:54:35 · 1 answers · asked by abby j 5

To make a solution with a pH = 3.80 a student used the following procedure :
a certain amount of sodium acetate along with 0.280 moles of acetic acid is added to enough water to make a solution of 1.00 L
How many grams of sodium acetate were added ?

Ka = 1.80 x 10-5

2007-03-19 15:53:43 · 1 answers · asked by tiggerx313 1

Which of the following solutions result in a buffer ?



a) 0.050 L of 0.250 M NH3 + 0.100 L of 0.250 M HCl


b) 0.100 L of 0.250 M NH4Cl + 0.050 L of 0.025 M HCl


c) 0.100 L of 0.250 M NH4Cl + 0.050 L of 0.250 M NaOH


d) 0.100 L of 0.250 M NH4Cl + 0.150 L of 0.250 M NaOH

2007-03-19 15:53:17 · 1 answers · asked by tiggerx313 1

Why do we have bad trips sometimes and not "good trips" all the time?

2007-03-19 15:49:32 · 5 answers · asked by dysastamami 2

OK the question is Explain how the arrangement of electrons in an atom is related to the periodic table.


Another question is which elements have properties similar to calcium????


thts the question so best answer gets 10 points
!!! please help !!!

2007-03-19 15:46:57 · 5 answers · asked by colorguardxfreak 2

2007-03-19 15:28:51 · 2 answers · asked by Lana 1

2007-03-19 15:27:10 · 5 answers · asked by Anonymous

A chemist heats 50g of sulfur under controlled conditions to produce a sulfur-oxygen compound. The mass of the sulfur-oxygen compound is 100g. What is the empirical formula of the sulfur-oxygen compound?

2007-03-19 15:25:26 · 4 answers · asked by Lana 1

I want to link up two cells, but the set-up is producing bad results. The individual series consist of two containers each with half-reactions. One is an aqueous reduction, and the other is a solid oxidation. My question is how do I link these up? I've tried hooking one's anode to the other's cathode, while using salt bridges between individual cells, but this has produced poor results. Please help!

2007-03-19 15:23:06 · 1 answers · asked by David K 2

i melted acetamide in a test tube in a calorimeter and was told to determine the heat of fusion. i have the mass of acetamide as 15g. temperature melting initiated at 80.1 C mass of water as 183.4g the intial calorimeter water temperature at 19.3 C and the final water temperature at 25.1 C

2007-03-19 15:06:55 · 1 answers · asked by triciaa4 1

You need 110 mol of water to fill his water bottle every day. how many moles of Hydrogen and Oxygen does he need to react to make 2 L of water?
*Use the equation - 2H2 + 02 --> 2H20
Steps please. Thanks :)

2007-03-19 14:55:33 · 1 answers · asked by kickitup21 1

the eqaution is: Fe+3 + SCN-1 = Fe(SCN)3(solid)

the question asks: What direction will the addition of KCl(solid) drive the equilibrium?

my question: i don't get it because KCL is not even in the equation so I do know where it would go???

2007-03-19 14:54:33 · 1 answers · asked by Tracey Lee ♥ 2

2007-03-19 14:51:24 · 5 answers · asked by darkraven_222000 1

2007-03-19 14:45:52 · 7 answers · asked by joncollins222 3

My equation is Fe+3 + SCN-1 = Fe(SCN)3solid

and it asks what direction do you think the addition of Fe+3 will drive the equilibrium

so my question is: how do I tell which direction it will go? left or right?

(were using the Le Chartelier's principle: any change to a chemical reaction at equilibrium causes the reaction to move in the direction that will minimize the effect of the change.)

2007-03-19 14:41:35 · 2 answers · asked by Tracey Lee ♥ 2

I'd like to develope a way to solidify oxygen, and have it able to be "time released", or released at a predetermined consistant rate, when exposed to Carbon Dioxide, to form breathable oxygen. Comments? ok, I'm not smart, but let me know what you think. Lemme have it..

2007-03-19 14:41:15 · 3 answers · asked by KidBao 3

What is the neutralization equation for acetic acid (CH3COOH) and sodium hydroxide, NaOH, i need it for titration

2007-03-19 14:20:41 · 4 answers · asked by Anonymous

If so can you write the reaction of iron(III)chloride and potassium thiocyanate

come on, i said please!

THANKS! ♥

2007-03-19 14:20:21 · 1 answers · asked by Tracey Lee ♥ 2

I'm looking for an answer that sounds more scientific and uses chemistry type terms, because, quite frankly, i need it for my chemistry paper. Thanks

2007-03-19 14:10:30 · 2 answers · asked by ? 2

potassium chloride
potassium nitrate
potassium sulfate

2007-03-19 14:08:16 · 2 answers · asked by Anonymous

A solution containing .10 mols of BaCl2 is mixed with a solution containing .20 mols of Na2SO4 to give a precipitate of BaSO4. What is the maximum percent yeild in moles of BaSO4? in grams?

2007-03-19 14:02:53 · 1 answers · asked by nickcasey829 1

http://i12.tinypic.com/2cngo05.jpg

in that picture, what arrow represents the heat of reaction (delta h) and which arrow represents the activation energy for the revese reaction?

thanks

2007-03-19 14:01:01 · 2 answers · asked by Krystal 2

2007-03-19 13:54:27 · 4 answers · asked by Vincebrwngodwithin 1

and the activation energy of the reverse reaction is equal to the..

1- potential energy of the product
2 - heat of reaction
3- potential energy of reactents
or 4 - activation complex

thanks, this is a review sheet and im stuck on some of the questions!

2007-03-19 13:48:38 · 3 answers · asked by Krystal 2

mass of nitrogen reacted = 3.75g
mass of oxide of nitrogen produced = 12.34g

a) what is the mas of oxygen reacted?...
12.34-3.75 rite?
b)what is the ration of the mass of nitrogen reacted to the mass of oxygen reacted?
(i have no idea)
c)using the mass ration in (b), calculate the mass of nitrongen that would react with 16.0 g of oxygen.
d) using a system of relative atomic mass, if we assign an atomic mass to oxygen of 16, what would be the relative atomic mass of nitrogen? assume 1 atom of nitrogen reacts with 1 atom of oxygen.
3) repreat (d) using the evidence that the formula for this oxide of nitrogen is NO2.
f) was the infomration givin in the evidenc suffiecient to determine the atomic mass of nitrogen relative to oxygen?
g) What addtional evidence was needed?

2007-03-19 13:45:10 · 2 answers · asked by no name 1

plz tell me rit now

2007-03-19 13:40:25 · 3 answers · asked by Chinty 4

does is crystalize or what does it do??

2007-03-19 13:39:22 · 2 answers · asked by Tracey Lee ♥ 2

The question reads Except for the Na+ Spectator ion, aqueous solutions of CH3COOH and CH3COONa contain the same species.

1) What are the species other than H2O
(i don't really get what this question is even asking)

2) Why is -1 M CH3COOH acidic and .1 M CH3COONa basic?

Any help is greatly appreciated

2007-03-19 13:37:40 · 3 answers · asked by meanest_pianist 2

Please help me!! I need to know this ASAP! If you can answer any parts please tell me the parts you know. I really need someone to walk me through each step if possible...like show work and all. Thanks so much.


A. What is the freezing point and boiling point of an aqueous solution of KCl that contains 105 grams of KCl in 625 mL of water?


B. An aqueous solution of an unknown solute is made by adding 43.8 grams of the solute to water. This solution lowers the freezing point of the water by 0.935 degrees C. What is the mass of the unknown solute?


C. A 778 gram sample of aqueous solution contains 133.0 grams of RbBr. The vapor pressure of pure water at 20 degrees C is 17.5 mm Hg. What is the vapor pressure of the water in the RbBr solution?

2007-03-19 13:31:11 · 2 answers · asked by XoswimXo 1

2007-03-19 13:29:47 · 4 answers · asked by strawberry 1