Aflask is charged with 0.124 mol of a and allowed to react to from b according to the reaction: a(g) -> b(g). the following drata are obtained for [a] as the reaction proceeds:
time: 0.00 10.0 20.0 30.0 40.0
moles of a: 0.124 0.110 0.088 0.073 0.054
a) what is the average rate of disapperance of a between 10s and 20s?
b) what is the avergae rate of disappearance of a between 20s and 40s?
c) what is the average rate of appearance of b between 20s and 30s?
d) how many moles of b are present at 10s?
e) how many moles of b are present at 30s?

A) -0.0022mol/s

B) -0.0017mol/s

C) 1.5x10^{-3}mol/s

D) 0.014molB

E) 0.051molB

Explanation:

Hello, here the answers:

A) Consumption.

B) Consumption.

C) Production.

Since the stoichiometric coefficients are 1 for both A and B, the consumed moles of A are equal to the difference between the initial moles of A and the actual moles of A, thus:

Now, the rate of appearance:

Which positive indeed because the moles are being formed.

Another way to find is by doing it directly with the moles of A since the rates are numerically equal but differing in the sign:

D) Based on the previous analysis:

E) Again:

molB_{30s}=0.124mol-0.073mol=0.051molB

Best regards.

c- cold periods in earth's history during which glaciers covered much of the surface.

explanation:

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