What is the oxidation number of phosphorus (p) in phosphoric acid (h3po4)? -7 +1 +5 +7

Hey there!:

H is always +1 so the H's have a +3 charge.

O is always -2 so the O's have a -8 charge .

Now, suppose oxidation state for P = X , then :

+3  + X + (-8) = 0      (because of neutral molecule)

x = 8 - 3

x = + 5

So, X = +5 oxidation state.

Answer  C

Hope that helps!

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation:

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.