Answer:
The correct answer is option C, that is, ΔS and ΔSsurr for the process H2O (s) ⇒ H2O(l) are equal in magnitude and opposite in sign.
Explanation:
The temperature at which solid state of water get transformed into liquid state is termed as the melting point of 0 °C. It can be shown by the reaction:
H2O (s) ⇒ H2O (l)
The degree of randomness of a molecule is known as entropy. With the transformation of ice into liquid state, there is an increase in randomness. Thus, the value of entropy becomes positive as shown:
Entropy change (ΔSsys) = ΔSproduct - ΔSreactant
= (69.9 - 47.89) J mol/K
= 22.0 J mol/K
Therefore, the value of entropy change is positive.
Now the value of entropy for surrounding ΔSsurr will be,
ΔSsurr = -ΔHfusion/T
= -6012 j/mol/273
= -22.0 J/molK
Hence, the value of ΔSsurr and ΔSsys exhibit same magnitude with opposite sign.
Answer:
12.78 kJ
Explanation:
The correct balanced reaction would be
Mass of methanol = 
Moles of methanol can be obtained by dividing the mass of methanol with its molar mass 
Enthalpy change for the number of moles is given by
The change in enthalpy is 12.78 kJ.
m = given mass of gas = 3.82 g
M = molar mass of gas = ?
T = temperature of laboratory = 302 K
P = air pressure = 1.04 atm = 1.04 x 101325 pa
V = volume of gas = 0.854 L = 0.854 x 10⁻³ m³
using the ideal gas equation
PV = (m/M) RT
inserting the above values
(1.04 x 101325) (0.854 x 10⁻³) = (3.82/M) (8.314) (302)
M = 106.6 g
hence the molar mass of the gas comes out to be 106.6 g
