7. One mole of phosphorous pentachloride contains how many of each of the following: a. phosphorous pentachloride molecules?
b. phosphorous atoms?
c. chloride atoms?
d. total atoms of all kinds?

a) 6.02 × 10^23

b)6.02×10^23

c)3.01×10^24

d) 3.612×10^24

In every mole of a substance there are 6.02×10^23 entities.

in ( c) there are 5 carbon atoms . 5 is multiplied by the number of moles of the molecule and then multiplied by 6.02×10^23. ( using the formula N=nL )

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.