The oxidation number of K in KOH is +1 because it is an alkali metal. Oxygen (O) typically has an oxidation number of -2 in compounds. Hydrogen (H) usually has an oxidation number of +1 in compounds. By applying these values, the oxidation number of KOH is -1.

In the tetrathionate ion (S4O6)2-, the total charge of the ion is 2-. Each oxygen atom has an oxidation number of -2, totaling -12 for all six oxygen atoms. Since the overall charge is 2-, the sum of the oxidation numbers of sulfur atoms must equal +2. With four sulfur atoms present, each sulfur atom in the tetrathionate ion has an oxidation number of +6.

The oxidation number for H in H4P2O7 is +1. Each hydrogen atom has an oxidation number of +1 because it is bonded to more electronegative elements like P and O, which have higher electronegativity values.

CN- group has an overall charge of -1. C has oxidation of +2 and N -3 in CN since N has more negativity than C. In other words, N competes and wins with C when both try to take electrons to satisfy their need to become stable. Cheers.

When calculating oxidation numbers, use '-2' (oxygen) as the 'yardstick'(standard).

Since SO3 has three oxygens, then the oxygen moiety is 3 x -2 = -6

Since SO3 is a neutrally charged molecule, overall oxidation is '0'.

Hence

S + -6 = 0

Hence S = 6 is the oxudation number for sulphur.

NB Sulphur exhibits different oxidation states in different molecules.

S = 0

SO2 = 4

SO3 = 6 ( as above)

H2SO4) = 6

H2S2O7 (Oleum) = 6

Elemental sulphur, like all other elements, has an oxidation number of zero(0).

However, when combined with other elements into molecules, it displays different oxidation number.s

H2S = -2

SO2 = +4

SO3 = +6

H2SO4 = + 6

HCN ( hydrogen cyanide) has the structurte H-C///N ( /// = triple bond).

The oxidation number of an atom is the number of outer most electrons used in forming a bond. Not all the outer most electrons are used, some can remain as 'lone pairs'.

Carbon ALWAYS has an oxidation no. of '+4' . It never varies. Hydrogen has an oxidaton number of '+1'. It is the nitrogen that has the variable oxidation. number.

HCN forms the ions , H^(+) & CN^(-)

Since carbon is always '4' and the overall charge of the ion is '-1' , then we can form a sum .

4 + N = -1

N = -1 -4

N = -5 is the oxid'n no/ of nitrogen in HCN. ( All five of nitrgens outer most electrons are involved in the bonding process. ). Compare with ammonia NH3 , Here nitrogen's oxid'n No. is '3' leaving a 'lone pair' of electrons not used in the outer most electron shell.

'4' .

Carbon atoms have four electrons in their outer energy shell. This leaves space to accept four more electrons to formvfour covalent bonds.

The oxidation number refers to the number of electrons in the outer energy shell that are used in combination with other atoms. Since carbon uses all four electrons , then its oxidation number is '4'.

Other elements, notably nitrogen have variable oxidation number.

Nitrgen when combined with hydrogen to form ammonia has an oxidation number of '3'. Because only three electrons out of the five electrons , in the outer energy shell, are used in combination with hydrogen.

In MnO2, the oxidation number of oxygen is typically -2. Since there are two oxygen atoms in MnO2, the total oxidation number contributed by oxygen is -4. The overall charge of the compound is neutral, so the oxidation number of manganese (Mn) can be calculated by setting the total oxidation number equal to zero. Therefore, the oxidation number of Mn in 2MnO2 is +4.

When calculating oxidation numbers, use '-2' for oxygen as a standard. It does vary in some oxygen molecules, but '-2' is a good starting point.

So in KNO3

The oxygen moiety is 3 x -2 = -6

Potassium(K) is always '+1' because it only loses one electron .

Hence the nitrgen os

+1 + N - 6 = 0

N- 5 = 0

N = +5 (oxidation state)

NB For neutrally charged molecule, the sum of the oxidation number is always 'zero'(0).

In PPh3, each phosphorus atom has an oxidation state of +3. The overall charge of the molecule would be neutral since there are three phenyl (Ph) groups, each with a -1 charge, balancing the +3 charge of the phosphorus atom.

Well, honey, the oxidation number of strontium in the hydride of strontium is +2. It's like asking if Betty White is a national treasure - the answer is obviously yes. So, in this case, strontium is happily rocking that +2 oxidation number like a boss.

-1

Well, isn't that a happy little question! In Na3PO3, the oxidation number for Na is +1 and for O is -2. Since the overall charge of Na3PO3 is neutral, we can calculate the oxidation number for P to be +3. Just remember, there are no mistakes in oxidation numbers, only happy little accidents!

The answer is +7 because the oxygen has a charge of -8 and the charge on the whole compound is -1 therefore the charge on Cl must be +7.

The structure of O2PtF6 is known and there is an O2 unit. The O2 is best formulated as O2+ ( dioxygenyl) and the oxidation number of each O atom is +1/2. (+0.5). This is an interesting compound PtF6 is a very stong oxidising agent.

K2SiO3 ( potassium silicate)

Use oxygen at '-2' as the starting point.

Since there are 3 x oxygen , then the oxygen component is 3 x -2 = -6

So the K & Si must sum to '+6'

Since K oxidises to '+1' as in 'K^+', then the 'K' component is 2 x 1 = 2

Hence we have 2 + Si + - 6 = 0 (neutral molecule)

Then by a simple sum Si is +4.

So the oxudation states of each element are

K = +1

Si = + 4

O = -2

The oxidation number of sulfur (S) in CaSO4 (calcium sulfate) is +6. This is because calcium (Ca) has an oxidation number of +2 and oxygen (O) almost always has an oxidation number of -2. Therefore, the sum of the oxidation numbers must equal zero for the compound CaSO4.

1. NH₄NO₃ (ammonium nitrate), the oxidation number of nitrogen in the NH₄⁺ ion is -3, and in the NO₃⁻ ion is +5. The overall charges balance with the ammonium ion being +1 and the nitrate ion being -1.

The oxidation number of Si in H2SiOF6 is +4. Oxygen has an oxidation number of -2, and since there are six oxygen atoms in the compound, the total charge from oxygen is -12. Hydrogen has an oxidation number of +1. Therefore, to balance the charges, Silicon must have an oxidation number of +4.

It can be, but not always so!!!!

For Groupos (I) & (II) the oxidation number is '1' & '2' respectively, the same as the ionic charge.

However, The Oxidation number can vary particularly in the Transition metals. It refers to the number of electrons in the outer (valence) energy shell , that acutally take part in the combination of a chemcial reaction.. NOT all electrons in the outer valence shell take part in a chemcial reaction.

For nitrogen in HNO3 it is '5'.

To calculate oxidation numbers.

1. Use oxygen as the stabndard at '-2'

2. -2 x 3 = -6 is the oxygen moiety.

3. Since hydrogen only oxides to '+1' as H^(+).

4. Create a little sum +1 +N - 6 = 0

To balance then N must be '+5'.

The phosphate anion is PO4^(3-)

Using oxygen as the standard at '-2' .

The nthe oxygen moiety is 4 X -2 = -8

Since the overall charge on the anion is '-3'

Then we can make a sum

P + - 8 = -3

Add '8' to bothe sides

P = +5 The oxidation state of phosphorus.

Alkali metals have a single electron in their outermost shell that is easily lost, resulting in a positive oxidation number. When they lose this electron to form ions, they attain a stable electron configuration, which typically involves having a full valence shell with a noble gas electron configuration.