Chemistry - August 2007

SiO2 is a high melting point solid?

2007-08-17 12:32:49 · 1 answers · asked by }{3@T 2

are these objects made of same or different metals? assume that calculated densities are accurate to 1.00 %

2007-08-17 10:46:35 · 7 answers · asked by mannu 2

Combined with chlroine, it produces a compound essential to life (I was thinking Sodium?)

A metal that occurs in vast limestone deposits and combines with oxygen to form an oxide with a formula MO.

The transition element at the center of hemoglobin

Used in smoke detectors and named for the United States

A component of washing powder mined in Death Valley

The basis for the compounds that make up all living thins

Primary constituent of pencil lead

The last element in the Periodic Table that is not radioactive

Exists as X4 molecules

The element named after the sun, where it was first detected


Thanks for the help guys.

2007-08-17 09:18:33 · 2 answers · asked by Hunter 2

Yellow lead oxide is always found in the ratio of lead to oxygen of 1000/77 Brown lead oxide is always found in the ratio of lead to oxygen of 1000/154 There is always twice as much oxygen in brown lead oxide as there is in yellow lead oxide. this is an example of wich law?

Law o definite Proportions

Law of multiple of Proportions

Law of conservstion of Matter

Law of conservation of Energy

2007-08-17 08:56:34 · 2 answers · asked by fuffy6yrfy d 1

When the same two elements make up more than one compound the mass ratio of the elements in one compared to the other will always be small whole number This is a staement of wich law?

Law od Coservation of Matter

Law of conservation of energy

Law of Multiple Proportions

Law Definite Proportions

2007-08-17 08:25:02 · 1 answers · asked by fuffy6yrfy d 1

When magnesium is bured in the presence of oxygen the magnesium and oxygen combine to produce magnesium oxide There are 6 grams of magesim and 4 grams of oxygen If 8 grams of magnesium oxide is produced and all the mageium was used up haow many grams of oxygen are left?

2007-08-17 08:17:35 · 3 answers · asked by Ken h 1

2007-08-17 08:14:36 · 1 answers · asked by Anonymous

Lavoisier

dalton

Berthollet

Proust

2007-08-17 08:03:08 · 3 answers · asked by Ken h 1

What are the uses for this material?

How much does it cost for a standard barrel (40 gallons US if memory serves)?

I was reading about a specialty chemical company that was going to build a facility to make this chemical from biomass, as opposed to buying it from a petroleum refiner.

Is this a good idea?

2007-08-17 07:44:34 · 1 answers · asked by Random Guy from Texas 4

Name two metals that you would not use. Explain your choices.

2007-08-17 07:05:48 · 3 answers · asked by Anonymous

Sodium chloride is acooman and vary compound its chemical formula ic NaCI. What is sodium chloride an example of?

a heterogeneous mixture

a pure substanc

a homogeneous mixture

none

2007-08-17 07:02:37 · 4 answers · asked by Ken h 1

solids

liquids

gases


molecules

1 2 and 3

2007-08-17 06:43:10 · 2 answers · asked by Anonymous

pure substance

electron

mixture

phase

2007-08-17 06:28:09 · 7 answers · asked by Anonymous

I have a solution with 2 different types of organic molecules. I meassured the absorbance of the solution with 2 different wavelenghs. How do I know which of the wavelengh is the maximum of each molecule by knowing their structure and chemical fomula (knowing number and kind of bonds etc) ?

2007-08-17 05:33:50 · 2 answers · asked by ohad n 1

Find the pH factor of a substance of your choice. Is this substance acidic or basic? Why?
Using this pH, show how to find the hydrogen ion content of the substance using the formula. Round to 10 decimal places or write your answer using scientific notation. Include units on your answer.

2007-08-17 05:31:52 · 2 answers · asked by Lennin V 1

PLEASE ONLY OBJECTIVE, SCIENTIFIC ANSWERS. I am not interested in any philisophical or religious takes on this issue. It would be great if I could start a dialogue amoung Chemists / Biochemists on this issue. (I am a Chemistry major at Ohio State and I just finished the third of three organic chem classes.)

2007-08-17 05:02:38 · 3 answers · asked by GKIRK78 2

2007-08-17 04:55:22 · 9 answers · asked by Anonymous

2007-08-17 04:31:48 · 2 answers · asked by nickoname 2

2007-08-17 03:43:39 · 10 answers · asked by Anonymous

A student attempted to determine d % by mass of nitrogen in Nitrochalk by d following titrimetric procedure.
2g of nitrochalk was heated with 25cm3 of 2.00M NaOH until no more NH3 was evolved.The mix. was filtered to remove d CaCO3.The filtrate was then made up to 250cm3 by adding distilled water and 25cm3 portion were titrated against 0.1M HCL.It was found that 30cm3 of acid was required to neutralize d NaOH left over.
1)From the given data,calc. d number of moles of ammonium nitrate present in the original sample of fertilizer
2)Calc. the % by mass of nitrogen in the fertilizer and
3)The % by mass of CaCO3 in d nitrochalk

Nitrochalk is a widely used fertilizer that conts NH4NO3 and CaCO3

2007-08-17 03:08:43 · 7 answers · asked by Emperor 3

anybody know any good website where i can find the aspirin synthesis, with beginning compound a phenol... thank u

2007-08-17 03:05:29 · 3 answers · asked by Anonymous

A mix. of CO and CO2 diffuse through a porous diaphragm in one half of d time taken for d same vol. or bromine vapour.What is the % composition by vol. of d mixture.

2007-08-17 02:57:02 · 3 answers · asked by Anonymous

2007-08-16 23:57:06 · 3 answers · asked by cherokeebabe 1

Na2CO3 + H2SO4 --> Na2SO4 + CO2 + H2O

first of all,,is this equation correct?
secondly,, i want to calculate the rate of this reaction,how do i do it?
suggest me an example of the concentrations and volumes of Na2CO3 and H2SO4 to be useful for calculating the rate of this reaction,
the whole experiment should take place within 1 and half hour,,

if this is a difficult one,,can u suggest me a simple but uncommon reaction,in the sense,,uncommon elements but easy to perform and fast,, for calculating its rate,,
now ,,2Na + Cl2 --> 2NaCl,,is so common,,i want an uncommon one,,

don't suggest about sodium and potassium,, my school lab doesn't have it,,

2007-08-16 23:19:01 · 1 answers · asked by gunkedar 2

2007-08-16 20:34:08 · 4 answers · asked by Anonymous

Ag(s) + SO42 (aq) + H+(aq) ───────> Ag+(aq) + SO2(g) + H2O(l)

(a) write the oxidation and reduction half reactions; (b) balance the overall equation;

(c) identify the species that is oxidised; (d) identify the species that is reduced.

please help

2007-08-16 20:27:57 · 1 answers · asked by Anonymous

what is the reaction with the litmus of the product of Magnesium powder with water after boilng ?
if turns blue/red then why? what equation involved?
please help !!!

2007-08-16 19:05:25 · 3 answers · asked by Anonymous

does magnesium powder react with h2o at ordinary temperature? and why?
at what instance that magnessium powder react with h2o?

2007-08-16 18:58:10 · 3 answers · asked by Anonymous

The question is: All fatty acids react with NaOH in a 1:1 mole ratio (this is a typical acid- base reaction). It is known that 125 mg of lauric acid is completely neutralized by 64.5 mg of NaOH. using this information and your answer to problem 5, determine the molecular formula of lauric acid.

Okay, so number 5 was: what mass is hydrogen will react with 15.00 grams of tungsten (VI) oxide, according to the following equation? WO3 (s) + 3 H2 (g) ==> W (s) + 3 H2O (l)

And for that problem (5) I got the answer to be .1957g H2

2007-08-16 18:38:20 · 3 answers · asked by Melody 2

Please list all the ways you believe chemistry affects your daily life. I am doing a survey to see how people use chemistry every day . I really appreciate it, Katie.

2007-08-16 18:01:19 · 5 answers · asked by Anonymous