I need a slide about chemistry... It may be about element but i looked about of fertiliser.... Please help me!!!

what is Percent Yield???

ok...
i am having a terrible amount of trouble with limiting and excess reactants...
here's my problem:
2. Some rocket engines use a mixture of hydrazine (N2H4) and hydrogen peroxide (H2O2) as the propellant system. The reaction produces nitrogen gas and water vapor.

a) Which is the limiting reactant in this reaction when 0.750 moles of hydrazine reacts with 0.500 mol of hydrogen peroxide?

for this part, i got 0.750 moles of N2, and 0.25 mol of H20...

b) How much of the excess reactant, in moles, remains unchanged?

0.5 moles of N2, right?

The average kinetic energy of a 1.85-g sample of argon gas in a 3.00-L bulb is 1.28e-22 J/atom.

What is the pressure of the gas?

What is the root mean square velocity of the argon atoms under these conditions?

Hi how would I go about explaining the reason why copper and gold are colored whereas silver is not??

Strange thing is that Cu, Ag and Au are all part of the same group in the Periodic table.

Did some research on the Net and I came up with energy differences in the d-orbitals that resulted in color, however, that does not explain why Ag is not colored. Would anyone like to help me on this issue??

Thanks in advance.

regards
scorpio_tkh

Are the charges on all transition metals going to be indicated by the roman numerial only? Morever, they are always positive charges correct?
Is this also correct that group 3A has a charge of +3, Group 4A= +or - 4, Group5A= -3, then next group 6A and 7A have charges of -2 and -1? Making sure my information is correct before I attempt balancing formula's.

Hello,

I am a first semester chemistry student in college taking Chem-1406 Essential/General Chemistry. I am working on an extra credit assignment that is supposed to be 22 slides long done in powerpoint. Well he gives us the criteria he wants on each slide about an element of our choosing but I am a little confused on what he means by "Properties" of calcium. Does he mean the subatomic particles or something else? Also he ask us to list the row in which our element is located. I don't know "rows" but I do know the groups and periods. Does "Row" fall into one of these two items?

Thank You,

The question:
Balance each of the following skeletal equations by using oxidation and reduction half reactions. All the reactions take place in acidic solution. Identify the oxidizing agent and reducing agent in each reaction.
a) Cl₂ (g) + S₂O₃^2-(aq) --> Cl^-(aq)+SO₄^2-(aq)

My answer so far:
Half Reaction for chlorine: Cl₂ + 2e^- --> Cl^-

This matched the back of the book

The problem:
The half reaction I wrote for S₂O₃ was completely different from what was in the back of the book.

I know that Magnesium is so reactive that when it burns, it reacts with the oxygen and nitrogen in the air. What would the name of the compound produced in this reaction be?

Help would be greatly appriciated. Thanks.

Hey, wonder if anyone could help me,

I am doing a back titration to determine the purity of a sample of aspirin. I have made up a standard solution of the aspirin in 50/50 water and ethanol, to dissolve it, and i have calculated the moles of this standard solution. I will then add 20cm^3 of this standard solution into a flask and then add 20cm^3 of NaOH. I have also calculated the moles of the NaOH required taking into consideration that excess will be required. But in order to hydrolyse the aspirin I need to work out what the concentration of the NaOH solution must be. What calculations would I have to do to work out the concentration of NaOH needed?