Answer:
In a favorable reaction, the free energy of the products is less than the free energy of the reactants.
Explanation:
The free energy of a system is the amount of a system's internal energy that is available to perform work. The different forms of free energy include Gibbs free energy and Helmholtz free energy.
In a system at constant temperature and pressure, the energy that can be converted into work or the amount of usable energy in that system is known as Gibbs free energy. In a system at constant temperature and volume, the energy that can be converted into work is known as Helmholtz free energy.
The change in free energy of a system is the maximum usable energy that is released or absorbed by a system when it goes from the initial state (i.e., all reactants) to the final state (i.e., all products).
In a chemical reaction, some bonds in the reactants are broken by absorbing energy and new bonds are formed in the products by releasing energy. As the reaction proceeds, the free energy of reactants is much greater than the products. As the products are formed, the concentration of reactants decreases and the difference in their free energy also decreases. This chemical reaction will occur until chemical equilibrium is achieved i.e., the free energy of the products and reactants is equal and the difference in their free energy is zero.
Answer:
A. Move the buret clamp to a ring stand with a larger base.
Explanation:
The ring stands are used to hold burettes, light in weight to avoid loss of stability, that is why it is necessary to change the size of the ring stand so that it can support the buret that we are going to use. It is not recommended to balance it with the hand since it would give us an inaccurate result in the titration.
Answer:
Explanation:
A solution of a weak base and its conjugate acid is a buffer.
The equation for the equilibrium is
The Henderson-Hasselbalch equation for a basic buffer is
![\text{pOH} = \text{p}K_{\text{b}} + \log\dfrac{[\text{BH}^{+}]}{\text{[B]}}](https://tex.z-dn.net/?f=%5Ctext%7BpOH%7D%20%3D%20%5Ctext%7Bp%7DK_%7B%5Ctext%7Bb%7D%7D%20%2B%20%5Clog%5Cdfrac%7B%5B%5Ctext%7BBH%7D%5E%7B%2B%7D%5D%7D%7B%5Ctext%7B%5BB%5D%7D%7D)
Data:
[B] = 0.400 mol·L⁻¹
[BH⁺] = 0.250 mol·L⁻¹
Kb = 4.4 × 10⁻⁴
Calculations:
(a) Calculate pKb
pKb = -log(4.4× 10⁻⁴) = 3.36
(b) Calculate the pH
Answer:The endpoint does not correspond exactly to the equivalence point
At the endpoint, a change in a physical quantity associated with the equivalence point occurs.
At the equivalence point, the mole number of equivalents of reagent added is equal to the mole number of equivalents of analyte present.
Explanation:
The end point is always indicated by some physical property that changes such as colour. At the equivalence point, the mole number of equivalents of reagent added is equal to the mole number of equivalents of analyte present. The equivalence point cannot be physically observed but can be deduced after a titration curve is plotted.
