Draw a lewis structure for the resonance form of aso4^-3, with the lowest possible formal charges. include any nonzero formal charges and lone pair electrons in the structure.
-what is the oxidation number of as
-what is the oxidation number of o

-) Lewis structure: See the figure 1

-) Oxidation number of As  = +5

-) Oxidation number of O =  -2

Explanation:

The first step is to calculate the total amount of electrons, for As we will have 5 electrons, for all the oxygens we will have 24 electrons (6 electrons for each atom) and finally we will have 3 more due to the charge (-3), so in total we will have: 5+24+3= 32 electrons.

In the lewis structure, we will have as central atom "As" then we have to put the oxygens around the central atom. In this case, As is an exception of the octet rule, in this structure  As would have 10 electrons and 8 electrons for each oxygen. So, in the total distribution of the electrons in the structure, we will have the 32 electrons that we calculate in the first step (figure 1).

Finally, in the oxidation number calculation, we have to start with the oxidation number of oxygen. The oxidation number of O is -2 then when we multiply by the number of atoms we will get -8, so the As must have an oxidation number of +5 in order to obtain a total charge of -3 (figure 2).

h let me think

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml