Answer:4
Explanation:To balance the equation you need to make the number of each element equivalent in both sides.
To start add a 2 in front of the MnO2 which balances the Mn.
Then balance the oxygen by adding a 4 in front of H20.
The H then needs a 8 as it’s coefficient.
The reaction that has the greatest tendency to be reversed in an spontaneous redox reaction is that whose forward standard reduction potential is the lowest (mos negative) one because that means that the reversed reaction will have the highest (most positive) standard reduction potential.
So, the answer is Cr(3+) + 3e- ---> Cr(s) with Eo = -0.91 V, whose reversed reaction is Cr(s) - 3e- ---> Cr (3+) with Eo = +0.91 V.
Answer: the second option Cr(3+) + 3e- ---> Cr(s) Eo = -0.91 V
Answer:
- The standard form of a chemical element is the natural mixture of several isotopes of the same element, which is atoms with the same number of protons but different number of neutrons, while an isotope is a particular kind of atom with a definite number of neutrons.
Explanation:
A <em>chemical element</em> is a pure substance formed by atoms with the same atomic number (number of protons). This is because it is the number of protons what identifies an element.
For example: oxygen is a chemical element, so oxygen is formed by only atoms of oxygen, and the atomic number of those atoms is 8, because every oxygen atom has 8 protons.
Nevertheless, some atoms of oxygen, may have different number of neutrons. Isotopes are different kind of atoms of the same element, which only differ in the number of neutrons. So, some atoms of oxygen will have 8 neutrons, other 9 neutrons, and other 10 neutrons (those are the stable isotopes of oxygen).
That difference in neutrons, is generally accepted that, does not modifiy substantially the chemical properties of the element, but the mass number. So, the isotopes with more neutrons wil be heavier, and the isotopes with less neutrons will be lighter.
- Mass number = number of protons + number of neutrons.
In general a chemical element is formed by a mixutre of isotopes of the same element.
The answer is 27 grams. Hope it helps
