Number of moles of FeCl2 used = mass/ molar mass
Number of moles = 507/126.751 = 4.
If one mole of Fe reacts with two moles of sodium
Then 4 moles of Fe produces 8 moles of sodium.
Number of moles of sodium = mass/molar mass
Molar mass of sodium chloride = 23 +35.5 = 58.5 g/mol
Hence mass = 8 * 58.5 = 468 g. Hence Option A.
Answer:
Group 2
Explanation:
The force pulling a tree down is the same that brings a skier to the lodge: food and beer. No, just kidding. Gravity. The parachuter in Group three also has gravity as a key force, but the reverse force of the air on the parachute is a key consideration to the problem, as well as to the parachuter. But it comes close.
Answer:
sulfur oxides and nitrogen oxides
Volume required for neutralization V will be:
V * 0.2125 M HCl = 25 mL * 0.17 M
V = 20 ml
First part:
When 10 mL is added we can apply Henderson equation to get the result, so:
The pH will be of basic buffer
pOH = pKb + log(salt/base)
or pOH = 4.19 + log (0.2125*10 / 25*0.17 - 10*0.2125 )
pOH = 4.19 and pH = 14 - 4.19 = 9.81
Second part:
When 20 ml is added, there is only salt formed
The pH will be salt of strong acid and weak base
So pH = 7 - 0.5 pKb - 0.5 log C
where C is the concentration of the salt formed so:
pH = 7 - (0.5*4.19) - (0.5 log (25*0.17) / (25+20))
= 5.42
Third part:
When 30 ml of the acid has been added,
The pH will be of the remaining strong acid
pH = - log (0.2125*10 / 25 + 30 )
= 1.326
I think the most appropriate answer is B !
as electrolysis is non spontaneous ! and it is also a redox rkn !