The freezing point of a substance is -20°C. Its boiling point is 120°C. a. At 80°C the substance is in the state
b. At -50°C the substance is in the state.
C. At 140°C the substance is in the state.

a. liquid

b. solid

c. gas, (should be at it's boiling point)

Explanation: If the normal melting point of a substance is below room temperature, the substance is a liquid at room temperature. Benzene melts at 6°C and boils at 80°C; it is a liquid at room temperature. If both the normal melting point and the normal boiling point are above room temperature, the substance is a solid.

if you need an explanation to each lmk

the answer is the first option

explanation:

just googled it m8. not that hard

lol

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