When a pure substance melts does its particles get larger
1 answer:
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Answer:
I. Kindly, see the attached image.
II. The reaction is exothermic.
III. - 51.88 kJ/mol.
IV. The reaction is spontaneous.
Explanation:
I. Draw a possible potential energy diagram of the reaction. Label the enthalpy of the reaction.
- Since the sign of ΔH is negative, the reaction is exothermic reaction.
In an exothermic reaction, the energy of the reactants is higher than that of the products.
<u><em>Kindly see the attached image to show you the potential energy diagram of the reaction.</em></u>
<em>II. Is the reaction endothermic or exothermic? Explain your answer.</em>
- The reaction is exothermic reaction.
- The sign of ΔH indicates wither the reaction is endothermic or exothermic one:
If the sign is positive, the reaction is endothermic.
If the sign is negative, the reaction is exothermic.
Herein, <em>ΔH = - 33.1 kJ/mol, </em>so the reaction is exothermic.
<em>III. What is the Gibbs free energy of the reaction at 25°C? </em>
∵ ΔG = ΔH - TΔS.
Where, ΔG is the Gibbs free energy change (J/mol).
ΔH is the enthalpy change (ΔH = - 33.1 kJ/mol).
T is the temperature (T = 25°C + 273 = 298 K).
ΔS is the entorpy change (ΔS = 63.02 J/mol.K = 0.06302 J/mol.K).
<em>∴ ΔG = ΔH - TΔS</em> = (- 33.1 kJ/mol) - (298 K)(0.06302 J/mol.K) = <em>- 51.88 kJ/mol.</em>
IV. Is the reaction spontaneous or nonspontaneous at 25°C?
The sign of ΔG indicates the spontaneity of the reaction:
If ΔG < 0, the reaction is spontaneous.
If ΔG = 0, the reaction is at equilibrium.
If ΔG > 0, the reaction is nonspontaneous.
Herein, <em>ΔG = - 51.88 kJ/mol, </em>so the reaction is spontaneous.
Answer:
44.8L of hydrogen gas
Explanation:
The reaction expression is given as:
2Na + 2H₂O → 2NaOH + H₂
Given parameters:
Mass of sodium = 92.4g
Unknown:
Volume of hydrogen gas = ?
Solution:
To solve this problem:
1 mole of a substance at STP occupies a volume of 22.4L
Let us find the number of moles of the hydrogen gas;
Number of moles of Na =
Molar mass of Na = 23g/mol
Number of moles = = 4.02mole
From the balanced reaction expression:
2 mole of Na will produce 1 mole of hydrogen gas
4.02 mole of Na will produce = 2mole of hydrogen gas
So
1 mole of a substance at STP occupies a volume of 22.4L
2 mole of hydrogen gas will occupy a volume of 2 x 22.4 = 44.8L of hydrogen gas
Answer:
Approximately 56.8 liters.
Assumption: this gas is an ideal gas, and this change in temperature is an isobaric process.
Explanation:
Assume that the gas here acts like an ideal gas. Assume that this process is isobaric (in other words, pressure on the gas stays the same.) By Charles's Law, the volume of an ideal gas is proportional to its absolute temperature when its pressure is constant. In other words
,
where
is the final volume,
is the initial volume,
is the final temperature in degrees Kelvins.
is the initial temperature in degrees Kelvins.
Convert the temperatures to degrees Kelvins:
.
.
Apply Charles's Law to find the new volume of this gas:
.