Answer:
0.00316
Explanation:
You have to use the following equation:
![pH=-log[H^+]](https://tex.z-dn.net/?f=pH%3D-log%5BH%5E%2B%5D)
You are given the pH and need to find the concentration of H+. Plug in the given components and solve.
![2.5=-log[H^+]\\H^+ = 10^{-2.5}\\H^+=0.00316](https://tex.z-dn.net/?f=2.5%3D-log%5BH%5E%2B%5D%5C%5CH%5E%2B%20%3D%2010%5E%7B-2.5%7D%5C%5CH%5E%2B%3D0.00316)
The concentration of H is 0.00316.
Answer;
(3) Substance A is an element and substance Z is a compound.
Explanation;
-A compound is a substance formed when two or more chemical elements are chemically bonded together, such as water, carbon dioxide, methane, etc while an element is a pure chemical substance made of same type of atoms, such includes, oxygen, potassium, hydrogen, carbon, etc.
- Compounds can be broken
down or decomposed into simpler substances: elements cannot be broken down chemically into simpler substances .
The answer is the option<span> 3.) Fixing a wineglass requires a large decrease in entropy.
Entropy is a termodynamical variable and it is defined as the degree of disorder of the system.
As per the second law of thermodynamics the spontaneous changes only occur when the entropy increases.
</span>Fixing the broken glasses by itself meant to decrease the entropy spontaneusly which violate the principle or second law of thermodynamics. So, it is not possible.