Answer:
indicator
Explanation:
Indicators are the weak organic dyes which shows different colors in acidic and basic mediums.
Due to the fact that a noticeable pH change occurs near the equivalence point of acid-base titrations, an indicator can be used to signal the end point of a titration.
Therefore, choosing the proper indicator, scientists can minimize the difference in these two numbers, allowing more accurate measurements in the lab.
Answer:
Atomic mass = 127.198 amu
Explanation:
The average atomic mass is obtained by summing the masses of the isotopes each multiplied by its abundance.
Atomic mass = (97.62 * 0.0825) + (109.3 * 0.2671) + (138.3 * 0.6504)
Atomic mass = 8.05365 + 29.19403 + 89.95032
Atomic mass = 127.198 amu
Answer:
The pH of the solution is 8.
Explanation:
To which options are correct, let us determine the concentration of the hydroxide ion, [OH-] and the pH of the solution. This is illustrated below:
1. The concentration of the hydroxide ion, [OH-] can be obtained as follow:
pOH = –Log [OH-]
pOH = 6
6 = –Log [OH-]
–6 = Log [OH-]
[OH-] = Antilog (–6)
[OH-] = 1x10^–6 mol/L
2. The pH of the solution can be obtained as follow:
pH + pOH = 14
pOH = 6
pH + 6 = 14
pH = 14 – 6
pH = 8.
From the calculations made above,
[OH-] = 1x10^–6 mol/L
pH = 8.
Therefore, the correct answer is:
The pH of the solution is 8
<span>This is an example of a substance changing state, a physical change, the molecules are changed, but the atoms themselves do not change, just their arrangement, and the mass of the molecules is the same. Therefor energy is absorbed by the molecules, as energy is required to change the state or physicality of a molecule structure.Hope this helps. Let me know if you need additional help!</span>
Bohr's atomic model may have not been the accurate atomic model we have in the present, but he helped paved the way for accurate discoveries. His model is also called the planetary model. The nucleus, containing the neutrons and protons are situated at the center of the atom. The electrons are orbiting around the nucleus. The model is illustrated as shown in the attached picture.
