Which is evidence that a chemical reagan occurred?
a. a phase change occurs
b. a new gas is observed in the form of bubbles
c. red and yellow paint mixing to make orange
d. the temperature of the substance remains constant updates

a new gas is observed in the form of bubbles

Explanation:

The only statement that was evidence of a chemical reaction is a new gas is observed in the form of bubbles Any time a new substance is created, a chemical reaction has taken place.

B) A new gas is observed in the form of bubbles.

Explanation:

Please trust me! Also take a break and drink water you've earned it <3

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