Hellium argon neon xenon krypton randon oxygen fluorine chlorine bromine
Answer: The correct answer is option B i.e., 2.78 mol
Explanation:
Aluminium reacts with iodine to form Aluminium iodide

From the equation, it is clear that 3 moles of iodine reacts with 2 moles of Aluminium to form Aluminium iodide
We know
For 2 moles of Aluminium, 
3 moles of Iodine reacts with 54 g of Aluminium
? moles of iodine react with 50 g of Aluminium
<span>According to Le Chatelier's Principle, the position of
equilibrium moves to counteract the change, the position of equilibrium
will move so that the concentration of
products of chemical reaction increase, if:</span>
<span>1) increase temperature, because this endothermic reaction.</span>
<span>2) increase concentration of reactant.</span>
<span>3) decrease pressure of the system, so reaction moves to direction where is more molecules.</span>
<span>
</span>
According to the reaction equation:
CH3COO- + H+ → CH3COOH
initial 0.25 0.15
change - 0.025 + 0.025
Equ (0.25-0.025) (0.15 + 0.025)
first, we have to get moles acetate and moles acetic acid:
moles of acetate = 0.25 - 0.025 = 0.225 moles
∴ [CH3COO-] = 0.225 mol / 1 L = 0.225 M
moles of acetic acid = 0.15 + 0.025 = 0.175 moles
∴ [ CH3COOH] = 0.175 mol / 1L = 0.175 M
Pka = -㏒ Ka
= -㏒ 1.8 x 10^-5
= 4.74
from H-H equation we can get the PH value:
PH = Pka + ㏒ [acetate / acetic acid]
PH = 4.74 + ㏒[0.225/0.175]
∴ PH = 4.8
The answer is c ..............::