Chemistry - October 2006

the first half is

Sr2+(aq) + 1IO3-(aq) ....

2006-10-23 11:37:00 · 1 answers · asked by lupering 3

The energy of the light emitted when a hydrogen electron goes from n = 2 to n = 1 is what fraction of its ground-state ionization energy?

2006-10-23 11:25:52 · 2 answers · asked by jasmine m 1

There are three parts to this question. 1. What is the meaning of the word "colorimetric"? 2. What must you vary in order to obtain a Beer's Law plot? and 3. To make a Beer's plot, what will u plot? Thanks for the help.

2006-10-23 11:13:50 · 1 answers · asked by Andrew 1

the recomended daily allowance of calcium is 1000 mg of Ca*2+ ions. calcium carbonate is used to supply the calcium in vitamin tablets. HOw many moles of calcium ions does 1000 mg represent? how many moles of calcium carbonate are needed to supply the required amount of calcium ions? what mass of calcium carbonate must each tablet contain?

2006-10-23 10:45:34 · 2 answers · asked by babycakez 3

2006-10-23 10:32:13 · 6 answers · asked by tapatel25 1

2006-10-23 10:19:38 · 6 answers · asked by steven d 3

what type of compound is CaCl2-?

a- acid
b- base
c- salt
d- protein
e- nucleic acid

2006-10-23 10:13:43 · 7 answers · asked by Amy_Lynn 1

Hey everyone,

For Chem class we're finding the empiricle formula for Barium Chloride Hydrate.

The following information is what I got in the lab.

Mass of crucible Lid -- 29.90 Grams Mass Curcible lid and hydrate -- 32.01 grams. Mass / crucible lid anhydrate after our 1st burning -- 31.69. And the second burning came up to 31.68 grams.

Our Chem teacher told us that we had to get the Mass of Hydrate and Anhydrate, and then find the moles of the Barium Chloride and Anhydrate? ((This is where I get confused)) Then we have to find the mol ratio of the two Barium chloride and Anhydrate?

We also have the Error Anlysis, which I know equals out to 2:1, since there are 2H2O in Barium Chloride. TH Theoretical yiled and the calculated observed mass should equal out to 2:1

Anyhelp would be greatly appreciated!!!

One confused Chem student

2006-10-23 10:01:49 · 2 answers · asked by Jordan M 1

Just how hot DOES sodium burn when it contacts water, as compared to more ordinary "household" burning materials such as oak wood, paraffin or vegetable oil, anthracite coal, etc.? Is it hot enough to have any effect on silica sand? I'm looking for comparative info for the sake of my fiction novel-writing. Also, will sodium still react with water if fine particles of it are held in suspension in any sort of liquid (that liquid itself possibly being something combustible) before water is introduced? I come up with ideas but don't understand enough chemical details to know if they'd work at all... :-)

2006-10-23 10:00:23 · 3 answers · asked by vermeil dragon 2

there are 5 protons and the weight is 10, if that helps any.

2006-10-23 09:57:55 · 5 answers · asked by steve_scharein 2

2006-10-23 09:30:34 · 25 answers · asked by Macca 1

A sample of lauric acid was heated above its melting point in a test tube and then cooled in a bath of water until it solidified. The termperature of the acid was measured as a function of time

Then they show a temp-time graph the starts up around 62 C and drops to 46 C and remains at a constant temp for the rest of the graph

1. what is the physical meaning of the flat region on the graph?
is it just that the temperature of the acid at the time is constant and the acid is changing state?

2. Use the graph to estimate the melting point.

Would it just be the 46 C where the graph starts going constant?

3. Is heat being absorbed or released as it solidifies?

I put released since it says it is cooled in a bath of water...meaning the heat goes to the surroundings.

Can you just tell me if thats correct

2006-10-23 09:29:45 · 1 answers · asked by Anonymous

2006-10-23 09:23:33 · 1 answers · asked by Rayados Monterrey 2

2006-10-23 09:17:39 · 1 answers · asked by Rayados Monterrey 2

2006-10-23 09:02:05 · 5 answers · asked by Lally 3

2006-10-23 08:57:54 · 4 answers · asked by aatif f 1

This is the q: There are 2 different isotopes for element Nailium. A representive sample of Nalium is in the container; there are 350 nails total. What is the (average) atomic mass of Nalium? What is the % abudance of each isotope in the mixture? How many white and black nails are in the container?

This is the information that was given to me:

* This is the equation used to solve the problem:
(abundance as a decimal x mass of all isotopes)

Mass of representive sample = 212.1 g

Mass of one white nail= .42 g

Mass of one black nail=.71 g


Please help thankz

2006-10-23 08:51:40 · 2 answers · asked by wat8besha 1

I'm trying to conduct an experiment, and I need these ingredients for it. it would be really convenient if anyone knows how to get these things from anything you can buy for really cheap at a store that you don't have to be like, 19 for chemicals.

2006-10-23 08:42:03 · 9 answers · asked by Anonymous

I'm updating a database of MSDS sheets. Previously, only the trade name was included but I would like to also include the chemical name. On products with numerous chemicals, which one is used? First in the list or the one with largest % by weight?
Thank you

2006-10-23 08:35:35 · 3 answers · asked by Laura 4

2006-10-23 08:29:05 · 3 answers · asked by Anonymous

What are van der waal forces?

2006-10-23 08:17:06 · 10 answers · asked by Bonkers 1

My HW question is "Write a slogan or catchy saying for your element." for potassium (K)

2006-10-23 08:10:41 · 12 answers · asked by Anonymous

2006-10-23 08:07:20 · 7 answers · asked by Anonymous

What diffrent types of acid are there how much of that acid is it made up of.

2006-10-23 08:01:03 · 2 answers · asked by nathan2484 2

This is more of a scientific question than an obvious reason why (i.e. it might explode).

2006-10-23 08:00:05 · 7 answers · asked by yoyo 2

2006-10-23 07:38:57 · 12 answers · asked by yoyo 2

2006-10-23 07:38:35 · 7 answers · asked by daredevil_archit 1

2006-10-23 07:26:54 · 4 answers · asked by lily 1

2006-10-23 07:13:49 · 6 answers · asked by Anonymous

1.) From CuSO4*H20, The first weight was 1.57g, when heated, .57g of Suso4 was Left, How many Moles of Water(H20) was Lost?

2.) Magnesium Acetate*H20, the first weight was .84g, when heated, .43g of Magnesium Acetate was left behind. How many Moles of Water(H20) was lost? Thanks! (Show how you got it)

2006-10-23 06:33:55 · 3 answers · asked by Anonymous