Chemistry - September 2007

I know it's calcuim carbonate, but when the calcium is with the hydrochloric acid, is there a colour change? Thanks.

2007-09-12 18:38:22 · 2 answers · asked by Anonymous

2007-09-12 18:29:10 · 4 answers · asked by Anonymous

One of the freons, CCl2F2, is manufactured by reacting carbon tetrachloride with hydrogen fluoride. The other reaction product is hydrogen chloride. What is the yield of this reaction, if a manufacturer obtains 160 kg of CCl2F2 from 280 kg of CCl4? (Enter the yield in percent.)

2007-09-12 17:59:13 · 1 answers · asked by danz2289 1

Any help is appreciated =)

An ionic compound forms when calcium (Z=20) reacts with iodine (Z=53). If a sample of the compound contains 8.98×1019 calcium ions, how many iodide ions does it contain?

2007-09-12 17:55:44 · 1 answers · asked by Anonymous

I have a Chemistry assignment and one of the questions are to write a balanced equation for my element, which is carbon.
What would be a balanced equation for carbon?

2007-09-12 17:44:36 · 2 answers · asked by hollow_stars 1

Describe the preparation of 2 liters of 0.05 M ammonium choloride buffer, pH 9.4, starting with 1 M NH4OH and 2.13 M HCL.

2007-09-12 17:38:50 · 2 answers · asked by jon st. germain 1

thank you ...

2007-09-12 17:25:30 · 1 answers · asked by azen 1

If possible, provide a formula
Help? Please. :)

2007-09-12 17:24:37 · 3 answers · asked by Anonymous

thank youu...

2007-09-12 17:23:04 · 1 answers · asked by azen 1

2007-09-12 16:56:30 · 2 answers · asked by knight19 1

2007-09-12 16:54:20 · 3 answers · asked by Anonymous

Any help is appreciated.

Classify each of the following substances as an element, compound, or mixture.

1. Vegtable soup

2. Butane

3. Calcium chloride, used to melt ice on roads, consists of two elements, calcium and chlorine, in fixed mass ratios

4. Gasoline

5. Sulfur

2007-09-12 16:49:34 · 6 answers · asked by Anonymous

2007-09-12 16:32:41 · 11 answers · asked by xxiangel 2

tnx

2007-09-12 16:18:20 · 6 answers · asked by Anonymous

An empty Erlenmeyer flask weighs 264.3 g. When filled with water (d = 1.00 g/cm3), the flask and its contents weigh 500.3 g.

a) What is the flask's volume?

b) How much does the flask weigh when filled with chloroform (d = 1.48 g/cm3)?

2007-09-12 16:07:15 · 4 answers · asked by Anonymous

A statement which summarizes the data obtained from a series of observations is known as a(n) ____.
observation
law
theory
conclusion
experiment

i think that is theory but i still confuse with conclusion

2007-09-12 15:19:54 · 5 answers · asked by phong pham 2

2007-09-12 15:10:52 · 13 answers · asked by Anonymous

how do u change 1.99945 to scientific notation WITH ONLY 3 significant figures?

2007-09-12 15:08:18 · 1 answers · asked by goofygoober 2

2007-09-12 15:06:28 · 6 answers · asked by motoson 4

I'd love to know your source as well, if you can. Giving out best answer. Thanks in advance!

2007-09-12 14:09:08 · 1 answers · asked by mar 2

i have this base
.............N(:)H
..............||
H2N(:) -C-N(:)H2 + H+

which site is more basic when you add H+, explain your choice using resonance structure

note (:) is one lone pair on N

2007-09-12 13:54:40 · 2 answers · asked by jennifer 2

Calicium has thee different isoptopes. 1 has a mass of 35.00 amu, another has a mass of 41.00 amu: and another has amass of 40.00 amu. what isotope is the most abundant of the three?

my answer = mass of 40.00 amu?

2007-09-12 13:48:04 · 2 answers · asked by nothinbutnet2009 4

heterogeneous compound, heterogeneous mixture, homogeneous mixture, or a homogeneous compound, and why?
Thanks in advance.

2007-09-12 13:46:45 · 3 answers · asked by Anonymous

2007-09-12 13:03:49 · 7 answers · asked by hheeyyssuupp 1

So I understand that diamonds are stronger than graphite, but diamonds have sp^3 bonds and graphite has sp^2 bonds. And supposedly, nanotubes with sp^2 bonds similiar to graphite are pretty darn strong too. How come graphite isn't stronger than diamonds with its sp^2 bonds?

2007-09-12 12:58:00 · 4 answers · asked by lena 1

Ok I'm stuck and there's no one to help me. So, PLEASE please pleeease if you know any one of these answers, don't hesitate to tell me. I promise to give best answer.

1. Demonstrate the dehydration synthesis and complete the following:
a) CH3(CH2)2COOH + CH3CH2NH2 -------> CH3CH2CH2CH2NHCOCH2 + H2O

d) .... -------> ethyl pentanoate + water (fill in the first part and state it in molecular formula)

2.
a) butyl ethanoate + water --------> ..... (fill in the second part and state in molecular formula

c) ... ------> CH3NH2 + CH3(CH2)4COOH (fill in the first part and state in molecular formula)

2007-09-12 12:42:45 · 1 answers · asked by Ivy K 3

2007-09-12 10:23:19 · 1 answers · asked by Adi 1

HELP! i'm at the beggining of year 10 and i am TOTALLY stuck on my homework
simple answers would be helpful
thanks
xxx

2007-09-12 09:51:58 · 2 answers · asked by Anonymous

How exactly are compounds with a number outside the bracket named? Would this be just Lead Nitrate? Or Lead (II) Nitrate? Or something completely different?

2007-09-12 09:50:34 · 7 answers · asked by azaa 3

Are the following ionic, non-polar covalent, or covalent???

1. HCl

2. MgO

3. NaCl

4. NaF

5. H2O

6. CaCl2

7. I2

8. O2

9. H2S

10. LiF

2007-09-12 09:47:41 · 1 answers · asked by frizzy_ghost 1