Answer:
(C) HClO, pKa = 7.54
Explanation:
A buffer is a solution that can resist abrupt changes in pH when acids or bases are added. It is formed by two components:
- A weak acid and its conjugate base.
- A weak base and its conjugate acid.
In this case, acid and base are defined according to Bronsted-Löwry theory, which states that acids are substances that <em>release H⁺</em> and bases are substances that <em>accept H⁺. </em>Therefore, when an acid loses an H⁺ transforms into its conjugated base. For example, HF/F⁻ is a conjugate acid-base pair.
In buffers, when an acid is added, it reacts with the base to diminish its amount:
F⁻ + H⁺ ⇄ HF
Also in buffers, when a base is added, it reacts with the acid to diminish its amount:
HF + OH⁻ = F⁻ + H₂O
The optimum pH range of work of a buffer system (known as buffer range) is between 1 unit less and 1 unit more of pH than its pKa.
So, the buffer formed by HClO/ClO⁻ works optimally in the pH range 6.54-8.54. Since pH = 8.10 is in that interval, this would be the optimal choice.
Answer:
number 29 is D
Explanation: When the moon orbits the earth some of the light reflects off the moon, making it visible on the Earth.
I dont know how to answer 28 fully, is there a picture?
When a solid is heated , the average kinetic e energy of the substance increases because of which the temperature increases....this heat won’t affect the average kinetic energy of the substance. Since average kinetic energy will remain same during phase change , the temperature will remain same too.
***HOPE THIS HELP YOU***
Answer:
B. The temperature of the water when the food sample has finished burning completely.
Explanation:
Heat or thermal energy is a form of energy that transfers from one object to another due to a temperature difference between the objects. The units for heat are joules or calories.
Calorimetry is the measurement of heat energy released or absorbed in a chemical reaction. A calorimeter is used in calorimetry. The calorimeter operates on the Law of Conservation of Energy which states that energy is never created or destroyed but is transformed from one form to another or between objects.
In food calorimetry, the energy released when food is burned is measured by recording the rise in temperature of water in a calorimeter when a given mass of a food sample is burned completely.
Energy can be calculated using the formula: Q = mc ∆T
where Q = the energy in joules or calories, m = the mass in grams, c = specific heat and ∆T = the change in temperature (final temperature - initial temperature).
The temperature of the water when the food sample has finished burning completely is taken as the final temperature of the water. The sample is allowed to smolder for sometime before recording the final water temperature. This is because the water temperature will continue to rise after the flame has gone out.
The turbine would stop generating electricity
