Chemistry - December 2007

Next year I planned on taking organic chemistry to fufill my pre med requirements but from what I hear, the course is extremely difficult.

I was wondering what makes organic chemistry so hard? Is the material really that difficult or is it just an insane amount of memorization? Maybe a mixture of both?

And is there anything I can do to prepare for organic chemistry to make my life easier?

Thanks for the help :)!

2007-12-28 06:16:09 · 6 answers · asked by ninja 2

The value ∆H = 6.01 kJ mol^-1

The value ∆S = 22.0 J K^-1

2007-12-28 05:59:19 · 4 answers · asked by Jerome D 1

10. Carbon tetrachloride may be prepared by the reaction of natural gas (methane CH4) and elemental chlorine gas in the presence of ultraviolet light. Write the UNBALANCED chemical equation for this process.

A. CH4 (g) + Cl2 (g) --------> C(Cl)4

11. Calcium oxide reacts with moisture in the air and is converted to calcium hydroxide. Write the UNBALANCED chemical equation for this process.

A. CaO (aq) + H2O (l) --------> CaOH

12. Ammonium nitrate breaks down into nitrogen gas, oxygen gas, and water vapor. Write the UNBALANCED chemical equation for this process.

A. NH4NO3 (aq) --------> N2 (g) +O2 (g) + H2O (g)

2007-12-28 05:52:18 · 2 answers · asked by Anonymous

Comment on each result and draw a possible structure for each sensible formula:
a) C4H6NO2
b) C5H12O3
c) C4H3N
d) C4H8CI4O2

2007-12-28 05:41:43 · 2 answers · asked by Jerome D 1

6. Silver will dissolve in concentrated nitric acid, producing NO gas and leaving a solution of silver nitrate in water. Write the UNBALANCED chemical equation for this process.

A. Ag (s) + HNO3 (aq) --------> NO (g) + AgNO3 (aq)

7. Calcium carbonate reacts by combining with hydrochloric acid, producing a solution of calcium chloride, converting the acid into water, and releasing carbon dioxide gas. Write the UNBALANCED chemical equation for this process.

A. CaCO3 (g) + HCl (aq) --------> CaCl2 (aq) + CO2

8. Hydrogen sulfide burns in air, producing sulfur dioxide gas and water vapor. Write the UNBALANCED chemical equation for this process.

A. H2S (g) --------> SO2 (g) + H2O (g)

9. The group 2 metals (Ba, C, Sr) can be produced in elemental state by the reaction of their oxides with aluminum metal at high temperatures, also producing solid aluminum oxide as a by-product. Write the UNBALANCED equation for the formation of ozone gas from oxygen gas.

A. What?

2007-12-28 05:38:11 · 2 answers · asked by Anonymous

The molar mass of Isotope A is 10.0 g/mol and % abundance is 19.9 %. The molar mass of Isotope B is 11.0 g/mol and % abundance is 80.1 %.

What is the average molar mass of this element?

What element is it?


=0 Help?

2007-12-28 05:24:09 · 2 answers · asked by Anonymous

If they are wrong can you tell me the right answer?

1. Balancing an question for a reaction ensures that the number of each type of atom is (blank) on both sides of the equation.

A: equal

2. How do we indicate the physical state of a substance when we write a chemical equation for a reaction?

A: Using either (s), (aq), (l), or (g)

3. In a chenical equation for a reaction, the notation "(aq)" after a substance's formula means that the substance is dissolved in (blank).

A. Liquid water

4. Propane (C3H8) burns in oxygen gas, producing carbon dioxide gas, water vapor, and heat. Write the UNBALANCED chemical equation for this process.

A. C3H8 (g) + O2 (g) --------> CO2 (g) + H2O (g) + heat

5. Pure hydrogen gas is ignited very carefully, the hydrogen burns gently, combining with the oxygen gas of the air to form water vapor. Write the UNBALANCED chemical equation for this reaction.

A. H2 (g) + O2 (g) --------> H2O (g)

2007-12-28 05:15:53 · 4 answers · asked by Anonymous

thanks :)

2007-12-28 05:13:28 · 5 answers · asked by Lilyan 1

2007-12-28 04:25:52 · 4 answers · asked by Vinny L 3

2007-12-28 04:18:55 · 6 answers · asked by screaming_weasel9 1

I was deep-frying papad made from mung bean and some black pepper in safola(brand's name) oil (containing edible Blended edible Vegetable oil which is a mixture of rice bran oil and kardi oil in ratio 3:7),...after frying i saw that the oil had turned black and got converted into jelly.......Can u tell WHY it happened

2007-12-28 04:14:13 · 3 answers · asked by sumit sinha 2

Nair Hair Remover Cream contains Potassium thioglycolate (article http://www.wired.com/science/discoveries/magazine/16-01/st_nair ). I've read articles that said anything with a "mer-" or "thio-" at the front of the name is derived from mercury. More to the point, the chemical potassium thioglycolate has a fact sheet here: http://hpd.nlm.nih.gov/cgi-bin/household/brands?tbl=chem&id=2071 which says it's also known as anything "mercapto-," such as Mercaptoacetic acid, and Potassium mercaptoacetate. So while I can't find anything specifically saying that these are all mercurials...wouldn't this make sense?

2007-12-28 04:02:39 · 4 answers · asked by cathy_cmr 3

2007-12-28 03:41:12 · 7 answers · asked by Essenes 1

Also is there any way of stopping this from happening in my flashlights?

2007-12-28 03:31:36 · 5 answers · asked by jack.marlinspike 3

HOW do you do symbol equations?
I am really confused!

2007-12-27 22:56:38 · 5 answers · asked by Anonymous

Why does it take this shape, using electron repulsion theory to expalin it., and explain how the shape accounts for the biological activity of HCN

2007-12-27 22:33:48 · 3 answers · asked by master 2

Pls provide the source and the chemical structure between EDTA and Chromium.

2007-12-27 22:21:36 · 2 answers · asked by watever 1

what are some good ways to write a CV to attract employers seeking organic/analytical chemists?
every chemical companies i have encountered are looking for chemists with EXPERIENCES. Are there any good chemistry graduate recruiting websites out there?
Thank u for ur time and consideration of my question!:)

2007-12-27 21:20:55 · 3 answers · asked by Anonymous

no imnot plannin on doin anything. just curiousity.

2007-12-27 19:31:43 · 2 answers · asked by Anonymous

Nate measures the mass of the sodium bicarbonate and observe that it weighs less than before. He exclaims, " Mark! Some of the powder has disappeared!" Mark has learnt a lot form his grade 8 Science lessons and explains that the powder has not disappeared.

1. What law does Mark refer his explanation to Nate?

2, What do you think Mark has said in his explanation?

2007-12-27 17:34:30 · 4 answers · asked by Anonymous

2007-12-27 15:27:03 · 4 answers · asked by daniel l 1

the raw materials like silica etc.

2007-12-27 14:49:53 · 6 answers · asked by Ajanthaa Thiagarajan 3

A) Combustion Reaction
B) Single- Replacement Reaction
C) Combination Reaction
D) Decompisition Reaction



Note: the ^ in the equation is an up arrow.

2007-12-27 13:54:55 · 4 answers · asked by Anonymous

A) Combustion Reaction
B) Single- Replacement Reaction
C) Combination Reaction
D) Decompisition Reaction

2007-12-27 13:48:24 · 3 answers · asked by Anonymous

A) Product
B) Reactant
C) Catalyst
D) Solid
E) Gas


Please help me out. thank you soo much

2007-12-27 13:45:50 · 5 answers · asked by Anonymous

A) The ways in which atoms are joined together are changed.
B) New atoms are formed as products.
C) The starting materials are named reactants.
D) The bonds of the reactants are broken and new bonds of the products are formed.
E) In a word equation representing a chemical reaction, the reactants are written on the left and the products on the right

2007-12-27 13:43:28 · 3 answers · asked by Anonymous

1: When sulfur dioxide decolorizes KMnO4, a product is MnS04. The valence of manganese changed from
+7 to +2
+6 to +4
+5 to +2
+4 to +2


2: The valence of Ti in TiO2 is
1
2
3
4


3: The formula for ferric sulfate is
FeSO4
Fe2SO4
Fe2(SO4)2
Fe2(SO4)3


4: One molecule of hydrogen is represented by the expression
H2
2H
2H+
2H-


5: The formula for nitrogen pentoxide is
NO2
N2O
N2O3
N2O5


6: The formula of sodium sulfite is
Na2S
Na2SO2
Na2SO3
Na2SO4


7: If the valence of element X is +2 and the valence of element Y is -3, the formula of the product when combined is
XY
X2Y3
X3Y2
X6Y6


8: The valence of sulfur in H2SO4 is
-6
-3
6
8


9: The formula for potassium sulfide is
K2S
KHSO3
K2SO3
K2SO4


10: The symbol for the element copper is
Co
C
Cr
Cu


11: The formula that shows chlorine with a valence of 7 is
HCl
HClO2
HClO3
HClO4


12: In K2CrO4, the valence number of Cr is
6
2
8
4


13: The symbol for lead is
P
Pb
Po
Pt


14: The symbol for silicon is
S
Sc
Si
Sn


15: The valence of the phosphorus in Na3PO4 is
-1
2
-3
5


16: The valence of aluminum is +3. The formula of aluminum sulfate is
Al2S3
AlSO4
Al2(SO4)3
Al2SO4


17: The number of electrons lost or gained in the outermost orbit of an atom is the atom's
atomic weight
atomic number
valence
molecular weight


18: The only common radical which has a positive valence is
SO4
NO3
NH4
CrO4


19: In the compound KClO3 the total negative valence is
-2
-4
-3
-6


20: What is the symbol for the element aluminum?
Ag
At
Al
Ar

2007-12-27 13:42:39 · 3 answers · asked by Ashley G 1

When the equation, Fe + Cl2 --> FeCl3 is balanced, what is the coefficient for Cl2?


PLease HelP

2007-12-27 13:33:19 · 6 answers · asked by Anonymous

Is CF3Cl polar? and what is its lewis structure? Because my teacher said any geometry with lone pair electrons on the center are polar. Except linear, square planer which are non polar. But isn't tetrahedral symmetrical and non polar also?

2007-12-27 13:19:48 · 3 answers · asked by Anonymous

i really need your help ASAP! and advance thanyou!

2007-12-27 13:14:34 · 5 answers · asked by Anonymous