Answer:
pH = 8.92
Explanation:
To solve this question we must know that the reaction of KOH with HC3H5O2 is:
KOH + HC3H5O2 → H2O + KC3H5O2
At equivalence point, all propanoic acid reacts to produce KC3H5O2.
This KC3H5O2 = C3H5O2⁻ is in equilibrium in water as follows:
C3H5O2⁻(aq) + H₂O(l) → OH⁻(aq) + HC3H5O2(aq)
<em>Where Kb = Kw / ka = 1x10⁻¹⁴/ 1.34x10⁻⁵ = 7.46x10⁻¹⁰</em>
is defined as:
Kb = 7.46x10⁻¹⁰ = [OH⁻] [HC3H5O2] / [C3H5O2⁻]
As both [OH⁻] [HC3H5O2] ions comes from the same equilibrium,
[OH⁻] = [HC3H5O2] = X
[C3H5O2⁻] is:
<em>Moles KOH = Moles </em>C3H5O2⁻:
0.0325L * (0.15mol / L) = 0.004875 moles
In 32.5 + 20mL = 52.5mL = 0.0525L:
0.004875 moles / 0.0525L = 0.09286M.
Replacing:
7.46x10⁻¹⁰ = [X] [X] / [0.09286M]
6.927x10⁻¹¹ = X²
X = 8.323x10⁻⁶M = [OH-]
As pOH = -log [OH-]
pOH = 5.08
pH = 14 -pOH
<h3>pH = 8.92</h3>
Answer:
Explanation:
Combustion reaction is given below,
C₂H₅OH(l) + 3O₂(g) ⇒ 2CO₂(g) + 3H₂O(g)
Provided that such a combustion has a normal enthalpy,
ΔH°rxn = -1270 kJ/mol
That would be 1 mol reacting to release of ethanol,
⇒ -1270 kJ of heat
Now,
0.383 Ethanol mol responds to release or unlock,
(c) Determine the final temperature of the air in the room after the combustion.
Given that :
specific heat c = 1.005 J/(g. °C)
m = 5.56 ×10⁴ g
Using the relation:
q = mcΔT
- 486.34 = 5.56 ×10⁴ × 1.005 × ΔT
ΔT= (486.34 × 1000 )/5.56×10⁴ × 1.005
ΔT= 836.88 °C
ΔT= T₂ - T₁
T₂ = ΔT + T₁
T₂ = 836.88 °C + 21.7°C
T₂ = 858.58 °C
Therefore, the final temperature of the air in the room after combustion is 858.58 °C
there is more air near sea level
When solid carbon reacts with oxygen gas to produce carbon dioxide gas. the deltaH (enthalpy change ) value is negative .DeltaH would be on the product side of the equation.
<h3>What is enthalpy change? </h3>
In a thermodynamic system, energy is measured by enthalpy. Enthalpy is a measure of a system's overall heat content and is equal to the system's internal energy plus the sum of its volume and pressure.
Knowing whether q is endothermic or exothermic allows one to characterise the relationship between q and H. An endothermic reaction is one that absorbs heat and demonstrates that heat from the environment is used in the reaction, hence q>0 (positive). For the aforementioned equation, under constant pressure and temperature, if q is positive, then H will also be positive. In a similar manner, heat is transferred to the environment when it is released during an exothermic reaction. Thus, q=0 (negative). Therefore, if q is negative, H will also be negative.
Learn more about enthalpy change here :
brainly.com/question/1445358
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