i have a headache of a chem problem (actually 5 headaches)

1. Magnesium reacts with HCl. Given the information below, what is the amount of Mg and HCl needed to do this reaction to fill a flask that holds 1 L?
Mg has a density of 1.74g/ml and 1 g of Mg requires 30.6 mL of an acid solution to react completely.

2. A sample of an organic compound (27.08g) was burnt in oxygen. The carbon dioxide formed weighed 53.31g and the water formed weighed 32.57g. what is the percent composition and empirical formula for the compound?

What and discuss are the limitations of models of ionic lattices, covalent molecular and covalent netowrk and metallic lattices.

I have this chemistry assignment, and I need to place the first 20 elements in reactivity order...

Is this possible? I was trying to do it first by the ionisation energies, but when comparing it to a metal reactivity series, it was different.

How do you place non-metals in reactivity order? Also, when going by the IE, i got Helium > Neon > Fluorine > Argon > Nitrogen > Oxygen....

Shouldnt it be Helium > Neon > Argon since they are all group 8 elements?

Okay, so I'm trying to balance the equation for the reaction between ethyl alcohol and boric acid. So far, this is what I've come up with:

C2H5OH+H3BO3==> ?

I'm pretty sure that it's a main type of reaction, but I'm stuck on figuring out the products. I'm also reasonably certain that it is an exothermic reaction.

Any help would be much appreciated. Thanks.

I am a student of aeronautical engineering. Due to a project, some people and me have been asked to do a project about the High-temperature Reusable Surface Insulation tiles, the HRSI, used in the US spacecrafts. I have found that they are made of 99,8% pure silica. I have been unable to found its price, the price of a single tile. However, I am trying to know how much does it cost to make the piece and the primitive material (99,8% pure silica).
My mates and me would be very pleased if someone could give us any information.
THANKS!!!

I have four unknown compounds and I need to solve their structures.

Here is some data about each one:

UNKNOWN #1
Iodoform test = positive
Fehling's test = negative
H20 soluble = yes

IR peaks: 1459, 1936, 2963, 3339

UNKNOWN #2
Iodoform test = negative
Fehling's test = positive (red brick precipitate)
H20 soluble = yes (already in aqueus solution)

IR peaks: none given

UNKNOWN #3
Iodoform test = positive
Fehling's test = negative
H20 soluble = yes

IR peaks: 1652, 1767, 1903, 2410, 2659, 2971

UNKNOWN #4
Iodoform test = positive (pale yellow precipitate bottom)

Doing an esterification practical in my Matric chem class today, we noticed that when the sulphuric acid was added to the mixture of 3-methylbutanol and ethanoic acid, the liquid around the boiling chips or glass beads (there were examples of each with the same result)became coloured browny-orange. Apparantly none of the chem teachers at our school can explain why this would happen, but it was happening consistently. Once the ester was distilled at the end of the procedure, the colour stayed with any ester that was undistilled. Can anyone explain why this would happen? Thanks.

Hi all,

I need to numerically evaluate integrals of the form <1s|1s>, <1s|z|1s>, and then <1s|z|npz> with n from 2 to 6. How do I do this? It needs to be done in a C++ program that I have written. I have all of the wavefunctions in the program, they are evaluated properly.

Can anyone help?

Thanks in advance

Hi. How do I find out how many oxygen atoms are in a certain number of grams of calcium phosphate? Thanks.

In my Chemistry II class, my teacher did an experiment involving dropping solid Sodium metal into a beaker filled with distilled water, which caused an explosion that shattered the beaker. After the experiment, he gave us this problem to answer, which counts as four test grades: