Answer:
<h2>0.088 moles</h2>Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
We have the final answer as
<h3>0.088 moles</h3>Hope this helps you
Given :
Molarity of acetic acid solution, M = 0.10 M.
pKa of acetic acid, pKa = 4.75 .
To Find :
Percentage dissociation of 0.10 M solution of acetic acid.
Solution :
We know,
Taking antilog both side, we get :
Since, acetic acid has 1 hydrogen atom to loose , so it is a monoprotic acid.
Now, percentage dissociation of monoprotic acid is given by :
Hence, this is the required solution.
Answer:
The images for the 3 sub-questions have been presented in the first, second and third attached image to this solution.
Explanation:
The reaction for the reaction between Hydrogen gas and Iodine to give Hydrogen iodide
H₂ (g) + I₂ (g) → 2 H I(g)
ΔH∘rxn = −9.5 kJ/mol r x n
a) From the information provided, the heat of reaction being negative shows that the reaction is an exothermic reaction with the products for an exothermic reaction having a lower energy content/level as the reactants for this reaction.
This shows that the energy diagram will have the products at a lower level than fe reactants.
The sketch of the energy diagram for this exothermic reaction is presented in the first attached image to this solution.
The heat of reaction is shown on the energy diagram, together with the activation energy, Ea, the heat content/energy level for the reactants (Hr) & products (Hr) and finally the ΔH∘rxn.
ΔH∘rxn = Hp - Hr
b) When a catalyst that speed up a chemical reaction is introduced to the chemical reaction, the catalyst goes about making the reaction faster by lowering the activation energy of the reaction.
The activation energy is the minimum energy that the reactants must possess to the able to form products. On the graph, it is denoted as Ea, the difference in energy between the peak of the curve and the emergy level of the reactants.
So, a catalyst will cause this activation energy to be lowered to a new level of Ea₁.
The energy diagram of this is presented in the second attached image to this answer.
The ΔH∘rxn remains unchanged for this introduction of catalyst.
The broken lines are used to represent the lowered activation energy action of the catalyst.
c) The reverse reaction will have opposite the energy properties of the initial reaction.
The initially exothermic reaction with higher heat content of reactants than products is now an endothermic reaction with heat content/energy level of the products higher than that of the reactants.
The energy diagram is presented in the third attached image.
The activation energy is bigger and the ΔH∘rxn is now positive and equal to 9.5 kJ/mol, the direct additive inverse of the ΔH∘rxn for the initial exothermic reaction.
Hope this Helps!!!
Answer:
The answer to the question is
The mass percentage of NaCl(s) in the mixture is 49.7%
Explanation:
The given variables are
mass of sample of mixture = 0.3146 g
Volume of AgNO₃ required to react comletely with the chloride ions = 45.70 mL
Concentration of the AgNO₃ added = 0.08765 M
The equations for the reactions oare
NaCl(aq) + AgNO₃ (aq) = AgCl(s) + NaNO₃(aq)
AgNO₃ (aq) + KBr (aq) → AgBr (s) + KNO₃
The equation for the reaction shows one mole of NaCl reacts with one mole of AgNO₃ to form one mole of AgCl
Thus 45.70 mL of 0.08765 M solution of AgNO₃ contains
Therefore the sum of the number of moles of Br⁻ and Cl⁻
precipitated out of the solution = 0.004 moles
Thus if the mass of NaCl in the sample = z then the mass of KBr = y
However the mass of the sample is given as 0.3146 g which means the molarity of the solution is 0.004 moles
given by
and z + y = 0.3146
Therefore z = 0.3146 - y which gives
-8.7×10⁻³y +0.54×10⁻³ = 0.004
or 8.7×10⁻³y = 1.37769× 10⁻³
y = 0.158 g and z = 0.156 Thus the mass of NaCl = 0.156 g and the mass percentage = 0.156/0.3146×100 = 49.7% NaCl
The mass percentage of NaCl(s) in the mixture is 49.7%