Archive for March, 2009
How many moles of NO3- ions are present in 220 mL of a 0.515 M Al(NO3)3 solution.?
The Chemistry answer
Al(NO3)3 will dissociate in solution to be:
Al(NO3)3 -> Al3+ + 3NO3-
from the reaction we know that one mole of Al(NO3)3 will produces 1 mole of Al3+ and 3 moles of NO3- ions. Thus we should find moles of Al(NO3)3 to find out moles of NO3-.
moles Al(NO3)3
= M x V
= 0.515 M x 220 mL
= 113.3 mmol
thus moles of NO3-
= 3 x mol Al(NO3)3
= 3 x 113.3 mmol
= 339.9 mmol
March 27th, 2009
how the atoms in lithium and fluorine transfer electrons to form ions?
Lithium atoms have tendencies to form positive atoms because these lithium is a metal. Beside that lithium has electron configuration of:
Li = 1s2 2s1
Thus these lithium atoms are prefer to lose their 1 electron that place in outer orbital to form lithium ion Li+. In another way fluorine is a nonmetallic atom thus fluorine is prefer to form negative ion because fluorine has 7 electron in its outer orbital thus to catch one electron will complete its octet rule, that is eight electron that place on the valence orbital.
F = 1s2 2s2p5
Li+ = 1s2
F- = 1s2 2s2p6
Thus lithium will give one electron to fluorine and then the form compound called lithium fluoride that connect with electrostatic force because of that this compound is belong to ionic coumpound.
or we can write the reaction below
Li -> Li+ + e
2e + F2 -> 2F-
and the whole reaction:
2Li + F2 -> 2LiF
March 27th, 2009
Chemistry Homework Problem
No, I’m NOT trying to get someone to do my homework. I’m just clarifying. My chemistry homework says:
“Was the product of the reaction between sodium carbonate and hydrochloric acid a solid, liquid or gas? How do you know?”
It looks like a liquid at the end, but the carbon dioxide is causing bubble, which would be gas. How do I explain this? Thanks.
Chemistry Answer
when you react sodium carbonate Na2CO3 with hydrochoric acid HCl that will be gas releases from the solution, the gas is CO2 and the other producth NaCl will still on the solution.
here the reactian equilibrium:
Na2CO3 + 2HCl -> 2NaCl + H2O + CO2
NaCl and H2O will stay in the solution and the Co2 will release out of the solution because it is gas.
March 27th, 2009