Answer:
i) The bond angle decreases due to the presence of lone pairs, which causes more repulsion on the bond pairs and as a result, the bond pairs tend to come closer. ii) The repulsion between electron pairs increases with an increase in electronegativity of the central atom and hence the bond angle increases.
Explanation:
Answer:
a) 1.61 mol
b) Al is limiting reactant
c) HBr is in excess
Explanation:
Given data:
Moles of Al = 3.22 mol
Moles of HBr = 4.96 mol
Moles of H₂ formed = ?
What is limiting reactant =
What is excess reactant = ?
Solution:
Chemical equation:
2Al + 2HBr → 2AlBr + H₂
Now we will compare the moles:
Al : H₂
2 : 1
3.22 : 1/2×3.22 = 1.61 mol
HBr : H₂
2 : 1
4.96 : 1/2×4.96 = 2.48 mol
The number of moles of H₂ produced by Al are less it will be limiting reactant while HBr is present in excess.
Moles of H₂ :
Number of moles of H₂ = 1.61 mol
Answer:
pH 9,8 is likely to work best for this separation
Explanation:
Ion exchange chromatography is a chemical process where molecules are separated by affinity to an ion exchange resin. To separate different aminoacids you must use the isoelectric point (That is the pH where the aminoacid will be in its neutral form).
For lysine, PI is:
9,8
For arginine:
10,75
At pH = 9,8 lysine will be in its neutral form and will not be retain in the column but arginine will be in +1 charge being retained by the ion exchange resin.
Thus, <em>pH 9,8 is likely to work best for this separation</em>
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I hope it helps!
Answer:
Explanation:
According to the boiling point elevation law described by the equation 
, the increase in boiling point is directly proportional to the van 't Hoff factor.
The van 't Hoff factor for nonelectrolytes is 1, while for ionic substances, it is equal to the number of moles of ions produced when 1 mole of salt dissolves.
would produce 2 moles of ions per 1 mole of dissolved substance, sodium and bromide ions.
is insoluble in water, so it would barely dissociate and wouldn't practically change the boiling point.
would dissociate into 3 moles of ions per 1 mole of substance, two potassium cations and one sulfide anion.
is a gas, it would form some amount of carbonic acid when dissolved, however, carbonic acid is molecular and would yield i value of i = 1.
Therefore, potassium sulfide would raise a liquid's boiling point the most if all concentrations are equal.
