Answer:Tthe liquid in a graduated cylinder curves up at the edge where the liquid meets the wall of the cylinder. This curve in the liquid is called the meniscus and is used to determiine the volume of liquid in a graduated cylinder by observing the measurement tick closest to the bottom of the meniscus.
Explanation:
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Answer:
Change in entropy for the reaction is
ΔS° = -268.13 J/K.mol
Explanation:
To calculate the change in entropy for the balanced reaction, we require the natural entropy of all the reactants and products in the reaction.
3 NO₂(g) + H₂O(l) → 2 HNO₃(l) + NO(g)
From Literature.
S°(NO₂) = 240.06 J/K.mol
S°(H₂O) = 69.91 J/K.mol
S°(HNO₃) = 155.60 J/K.mol
S°(NO) = 210.76 J/K.mol
These are the entropies of the reactants and products under standard conditions of 298.15 K and 1 atm.
Note that
ΔS° = Σ nᵢS°(for products) - Σ nᵢS°(for reactants)
Σ nᵢS°(for products) = [2 × S°(HNO₃)] + [1 × S°(NO)]
= (2 × 155.60) + (1 × 210.76) = 521.96 J/K.mol
Σ nᵢS°(for reactants) = [3 × S°(NO₂)] + [1 × S°(H₂O)]
= (3 × 240.06) + (1 × 69.91) =790.09 J/K.mol
ΔS° = Σ nᵢS°(for products) - Σ nᵢS°(for reactants)
ΔS° = 521.96 - 790.09 = -268.13 J/K.mol
Hope this Helps!!
When heated, particles vibrate faster, thus increasing the distance between one another. The distance between these particles results in changes of state. Therefore, increased molecular motion results in expansion of an object. This works vice versa for cooling. As the vibrations slow down, the particles become closer together. This results in contraction.
Answer:Cell reaction is going forward.
Explanation:
For any chemical reaction to be spontaneous or to move in forward direction the ΔG ,the Gibbs free energy must be negative.
The cell potential of a battery is positive for a spontaneous reaction, so for a battery to give output its cell potential must be positive.
Thermodynamics and electro-chemistry are related in the following manner:
ΔG=-nFE
n=number of electrons involved
F=Faradays constant
E=cell pottential of battery
so from the above equation ΔG would only be negative when E cell that is the cell potential is positive.
For a battery which is being used its cell potential is positive and hence the ΔG would be negative. So the cell reaction occurring would be in forward direction as ΔG is negative.
when the cell potential Ecell is 0 then ΔG is also zero then the reaction occurring in battery would be at equilibrium.
When the cell potential Ecell is - then ΔG is positive and the reaction would be occurring backwards.
