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• Users: carle
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1. ### Solubility - solubility product

Hm.. but in 2) [Mg2+ is unknown, how do I calculate that?
2. ### Solubility - solubility product

1 i) The reaction will be Co(OH)2 ⇔ Co2+ + 2OH- so Ks = [Co2+][OH-]2 which gives (5.4*10-6)*(2*5,4*10-6)2 = 6,3*10-16. ii) pH is 10.43 so pOH = 3.57 and [OH-] = 10-3.57. I think that I need to do some kind of schedule between the mole ratios, because I can see that the concentration ratio...
3. ### Solubility - solubility product

Hello! Two questions that I would like to get some help with. I'm translating these so I hope I get it right. 1. The solubility of cobalt(II)hydroxide is 5.4*10^-6 moles/dm^3 in water. i) What is the solubility product? ii) What is the solubility of cobalt(II)hydroxide if pH is buffered to...
4. ### Molecular orbital configurations (bond order and electron config.)

Hey guys. I'm a little confused about calculating the bond order and choosing the correct electron configuration. Compare these two calculations (from my textbook): http://oi44.tinypic.com/2vt8krp.jpg and http://oi39.tinypic.com/sv19hc.jpg As you can see, the electron configuration for...
5. ### Ionization energy - compare 2 unknown elements and decide their group

Yes, I know what valence electrons are; the electrons in an atoms outer shell. Group 13 elements have 3 valence electrons. Then I figure that in the first, second and third ionization energy levels you have removed 1, 2 and 3 of the group 13 valence electrons, so that there are no valence...
6. ### Ionization energy - compare 2 unknown elements and decide their group

I'm sorry, but this leads me nowhere, so I'll be better off if someone simply could give me an explanation of why it is group 13.
7. ### Ionization energy - compare 2 unknown elements and decide their group

4. Which tells me.. ?
8. ### Ionization energy - compare 2 unknown elements and decide their group

Well, is it because the first three energy levels remove all the group 13 valence electrons, and then you need much more energy to remove one more electron? But wouldn't it require much energy to remove the last valence electron in any element, so why can't it be for example group 14 loosing 4...
9. ### Ionization energy - compare 2 unknown elements and decide their group

Hello. I have a question about ionization energy: Two hypothetical elements in the 2nd or 3rd period have the following ionization energies: Element X First: 800 kJ/mol Second: 2500 kJ/mol Third: 3900 kJ/mol Fourth: 23000 kJ/mol Element Y First: 700 kJ/mol Second: 2200 kJ/mol...
10. ### Calculating the driving force in a double-acting cylinder using air

I've replied! Thank you.
11. ### Calculating the driving force in a double-acting cylinder using air

Thank you for your reply! I need a little more help though (I'm very new to this); can I use the ideal gas law to calculate the pressure needed to give enough torque for the car to go forward (20N), or how do I do that? In an ideal state, p2 should be 1 atm, but how do I determine v2 and v1? Do...
12. ### Calculating the driving force in a double-acting cylinder using air

Hello! I'm completely lost trying to derive an equation that'll give me the driving force in a DAC, and I really need some help from you guys. The purpose of knowing this is to optimize the amount of air that is needed (24 litres are available, pressure up to 8 bar) to drive a...