Explanation:
In general, to balance an equation, here are the things we need to do:
Count the atoms of each element in the reactants and the products.
Use coefficients; place them in front of the compounds as needed.
<span>The answer is anions. Cations are positively-charged ions (in this case K+) while anions are negatively-charged ions (in this case Cl-). The ions attract each other through electrostatic charges and arrange themselves in an ordered fashion to form a lattice</span>
A. Zn²⁺
<h3>Further explanation</h3>
Given
Cations of several elements
Required
The least to be reduced
Solution
If we look at the voltaic series:
<em>Li-K-Ba-Ca-Na-Mg-Al-Mn- (H2O) -Zn-Cr-Fe²⁺-Cd-Co-Ni-Sn-Pb- (H) -Cu-Hg-Fe³⁺-Ag-Pt-Au </em>
The electrode which is easier to reduce than the hydrogen (H2) electrode has a positive sign (E red= +) and is located to the right of the voltaic series (right of H)
The electrode which is easier to oxidize than the hydrogen (H2) electrode and is difficult to experience reduction has a negative sign (E red= -) and is located to the left of the voltaic series (left of H)
Or you can look at the standard reduction potential value of the metals in the answer options, and the most negative reduction E° value which will be difficult to reduce.
The Zn metal is located far left of the other metals in the answer choices, so it is the most difficult to reduce
Number of moles = 5.7 moles of oxygen.
<u>Explanation:</u>
We have to convert number of molecules into number of moles by dividing the number of molecules by Avogadro's number.
Here number of molecules of oxygen given is 34.1 × 10²³ molecules.
Now we have to divide the number of molecules by Avogadro's number as,
Number of moles = 
= 
= 5.7 moles
So here molecules is converted into moles.
A chemical reaction is a reaction that forms a new substance and it is also a reaction that s permanent ( you cannot reverse)