# Search results

1. ### Help on empirical formula

Vitamin B5 is called niacin or nicotinic acid. Its percentage composition by mass is (58.4% Carbon) (4.09% Hydrogen) (25.99% Oxygen) and (11.38% Nitrogen). What is the empirical formula of vitamin B5?
2. ### Organic Compounds Structural Formula

when drawing the structural formula for 2-methylbutane or 2,3-dichloro-2-methylbutane,does it matter which end of the chain i begin counting from?

thankyou
4. ### Period 3 ionization energy

i am stuck on this question and people are giving me different answers. Ok which period 3 element has the following succesive ionization energies: 1800,3000,3600,5800,13200
5. ### Succesive Ionization Energies

The succesive ionization energies in kj/mol of an element x found in period 3 of the periodic table are: 1800,3000,3600,5800,13200. With the aid of a periodic table,what is element x?
6. ### Electronic configuration

Galium has 3 positive ions. So i guess Nitrogen have 3 negative ions and therefore gaining 3 electrons.
7. ### Electronic configuration

here is my problem. Galium Nitride is an Ionic Compound. Work out the electron arrangement of the Nitrogen ion
8. ### Concenctration of a mass

0.0005mol/dm3
9. ### Concenctration of a mass

M is concentration. There are two ways of writing it,M or mol/dm3
10. ### Concenctration of a mass

Concentration=moles/volume Moles = mass/atomic mass, 5.8g/Na2C03 So 5.8/106=0.005moles. Conc=0.05/100=0.0005M. So?
11. ### Concenctration of a mass

I found concentration to be 0.0005M. Could you confirm if this is correct?
12. ### Concenctration of a mass

Mass of Na2CO3 is 5.8g
13. ### Concenctration of a mass

Hi guys,here is my question. What is the Concentration of Na2CO3 when it dissolves in a solution and forms a volume of 100 cubic cm? Concentration= moles/volume. I found moles using mass/atomic mass of Na2+C+03. Then i used moles/volume to calculate concentration. Correct?
14. ### Mole Concept

How many Gold atoms are in Gold mass of 2.5g? 15 percent of the mass is pure Gold. So first i found 15 percent of the mass which i used to calculate the number of moles. Then i multiplied the moles by Avogadros number to give me the atoms. Anyone help