Answer:
Option C. 88 KJ
Explanation:
The activation energy (Ea) is the minimum energy that reactant must overcome in order for them to proceed to product.
In an energy profile diagram, the activation energy (Ea) is obtained by calculating the difference between the energy of the activation complex (i.e peak) and the energy of the reactant.
With the above information, we shall determine the activation energy (Ea) of the reaction above as follow:
Activation complex = 268.74 KJ
Energy of reactant = 180.74 KJ
Activation energy (Ea) =?
Activation energy = Activation complex – Energy of reactant
Activation energy = 268.74 – 180.74
Activation energy = 88 KJ
Therefore, the activation energy (Ea) of the reaction is 88 KJ
Answer:
You need to add 19,5 mmol of acetates
Explanation:
Using the Henderson-Hasselbalch equation:
pH = pKa + log₁₀ [base]/[acid]
For the buffer of acetates:
pH = pKa + log₁₀ [CH₃COO⁻]/[CH₃COOH]
As pH you want is 5,03, pka is 4,74 and milimoles of acetic acid are 10:
5,03 = 4,74 + log₁₀ [CH₃COO⁻]/[10]
1,95 = [CH₃COO⁻]/[10]
<em>[CH₃COO⁻] = 19,5 milimoles</em>
Thus, to produce an acetate buffer of 5,03 having 10 mmol of acetic acid, you need to add 19,5 mmol of acetates.
I hope it helps!
Answer:
Approximately 0.39 g or 0.4 g if you're rounding up
Explanation:
15/3.82 = 3.92
Let's round that up to 4
That means 15 days is around 4 half lives
4 half lives means 1/16 of the original mass will be left
25/16 = 0.390625
In redox reactions, there is no net loss or gain of electrons, so the answer is (1) equal to the total number of electrons gained
We have to know the solubility of CaF₂.
The solubility of CaF₂ is: (c) 2.1 x 10-4 Molar
The general expression of solubility product of any sparingly soluble salt (having solubility S) with formula 
is: 
.
For the compound, CaF₂, x=1, y=2 So, 
=
=4S³= 3.9 x 10-11 (Given)
S³=
S³=9.75 X 
S= 2.1 X 
Molar
