Which rule for assigning oxidation numbers is correct?
2 answers:
<em>Oxygen with an oxidation number -2 is the correct oxidation number</em>
<h3><em>Further explanation</em></h3>The formula for determining Oxidation Numbers in general:
- 1. The number of oxidation of single element atoms = 0. Examples of Ar, Mg, Cu, Fe, N₂, O₂, etc. = 0
Group IA (Li, Na, K, Rb, Cs, and Fr): +1
Group IIA (Be, Mg, Ca, Sr and Ba): +2
H in compound = +1, except metal hydride compounds (Hydrogen which binds IA or IIA groups) oxidation number H = -1, for example, LiH, MgH₂, etc.
- 2. Oxidation number O in compound = -2, except OF2 = + 2 and in peroxide (Na₂O₂, BaO₂) = -1 and superoxide, for example KO₂ = -1/2.
- 3 The oxidation number in a non-filled compound = 0,
The total amount of oxidation in ion = ion charge, Example NO₃⁻ = -1
If we see the choice of answers
- 1. Hydrogen is usually –1.
This statement is wrong because generally the value of H is +1 except for the Hydride metal
- 2. Oxygen is usually –2
This statement is true, except the oxygen content of OF2, peroxide and superoxide compounds
- 3. A pure group 1 element is +1
In the form of a single or pure element, all the classes of oxidation are 0, so this statement is wrong
- 4. A monatomic ion is 0
Monoatomic ions consist of one ion atom is composed of several atoms called polyatomic ions
Monoatomic ion is dependent on the ion, such as H + oxidation +1, Ca2 + oxidation +2 etc. So this statement is wrong
<h3><em>Learn more</em></h3>Assign an oxidation number to each element
the reduction process
an element's oxidation
an element's oxidation number increase
Keywords: monoatomic ion, element, The oxidation number
You might be interested in
<u>Answer:</u> The molecular formula for the menthol is
<u>Explanation:</u>
The chemical equation for the combustion of hydrocarbon having carbon, hydrogen and oxygen follows:
where, 'x', 'y' and 'z' are the subscripts of Carbon, hydrogen and oxygen respectively.
We are given:
Mass of
Mass of
We know that:
Molar mass of carbon dioxide = 44 g/mol
Molar mass of water = 18 g/mol
- <u>For calculating the mass of carbon:</u>
In 44g of carbon dioxide, 12 g of carbon is contained.
So, in 0.2829 g of carbon dioxide, of carbon will be contained.
- <u>For calculating the mass of hydrogen:</u>
In 18g of water, 2 g of hydrogen is contained.
So, in 0.1159 g of water, of hydrogen will be contained.
- Mass of oxygen in the compound = (0.1005) - (0.077 + 0.0129) = 0.0106 g
To formulate the empirical formula, we need to follow some steps:
- <u>Step 1:</u> Converting the given masses into moles.
Moles of Carbon =
Moles of Hydrogen =
Moles of Oxygen =
- <u>Step 2:</u> Calculating the mole ratio of the given elements.
For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.00066 moles.
For Carbon =
For Hydrogen =
For Oxygen =
- <u>Step 3:</u> Taking the mole ratio as their subscripts.
The ratio of C : H : O = 10 : 20 : 1
Hence, the empirical formula for the given compound is
For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.
The equation used to calculate the valency is :
We are given:
Mass of molecular formula = 156.27 g/mol
Mass of empirical formula = 156 g/mol
Putting values in above equation, we get:
Multiplying this valency by the subscript of every element of empirical formula, we get:
Thus, the molecular formula for the menthol is