Gallium (Ga, 69.723 g/mol) is a metalloid obtained from its salts during the smelting of ores of other elements, like Zinc. has broad applicability in the electronics industry. It is also used as a safe replacement for mercury in thermometers as it melts at 29.8 °C and has a heat of fusion of 5.59 kJ/mol. What is the entropy change of 22 g of gallium in J/K as it melts when placed on a surface at 29.8°C?

4.255 J/ K

Explanation:

Given data :

mass of Gallium = 16 gm

molar mass = 69.723 g/mol

hence no of moles = 16 / 69.723 = 0.23 moles ( 1 )

Δh ( heat fusion ) = 5.59 KJ/mol

Temperature = 29.8°C = 302.8 k

Determine the entropy change of gallium

Δs ( entropy change ) =  heat fusion / temperature

 = ( 5.59 * 1000) J/mol / 302.8 = 18.46 J/k*mol

Hence entropy change of gallium

= Δs * no of Gallium moles

= 18.46 * 0.23 = 4.255 J/ k

I hope this is right haha

explanation: it gains negative electrons, therefore becoming negatively charged. as charge cannot be created, nor destroyed, only transferred, this leaves the wool positive. now that they have opposite charges, the two items attract.

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