Which of the following observations NOT likely describes a chemical change? a A white solid was exposed to ultraviolet light and turned brown. b Two clear liquids were mixed together and a yellow solid formed c A solid was added to water and the mixture was stirred until the solid was no longer visible d A piece of metal was added to a liquid and bubbles formed on the surface of the metal

The correct answer would be - c.  A solid was added to water and the mixture was stirred until the solid was no longer visible

Explanation:

Photostabalizing is the process where a solid change its color in the presence of ultraviolet light, it is a chemical change, so the first option would not be the correct answer.

when two liquid or aqueous solutions are mixed together and form a solid substance, this reaction is known as precipitation and it is a chemical reaction too.

When a solid is placed in a liquid and after stirring it makes the solid vanish is a physical change known as dissolving character.

Thus, the correct answer is option C.

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