A physical change is a change to a sample of matter in which some properties of the material change, but the identity of the matter does not. Physical changes can further be classified as reversible or irreversible. The melted ice cube may be refrozen, so melting is a reversible physical change.
Answer:
9.2 grams of ethanol should be added.
Explanation:
Let the mass of ethanol be x
Density of an ethanol = 
Volume of the ethanol =
Mass of chloroform = 5.0 g
Density of an chloroform= 
Volume of the ethanol =
Mass of the mixture,m = x + 5.0 g
Density of the mixture = 
Volume of the mixture=
Solving for x , we get
x = 9.2 g
9.2 grams of ethanol should be added.
This is answer open this image I am not sure is this wright
Delta Go = -RTlnKeq
delta Go = 5.95 kJ/mole = 5.95 X 1000 = 5950 J/mole ( 1 kj = 1000 J )
putting the values and finding Keq
5950 = -8.314 X 298 X ln Keq
ln Keq = -5950 / 2477.572 = -2.4015
Keq = e^-2.402 = 0.0905
suppose the equilibrium reaction is :-
chair 1 <--------> chair 2
now as Keq is less than 1 ....so chair 1 will be more stable
Keq = [chair2]/[chair 1 ] = 0.0905
this means that [chair 2] ~ 0.0905 and [chair 1] ~ 1
[total] = [chair 2] + [chair 1] ~ 1 + 0.0905= 1.0905
percentage of chair 1 = [chair 1] / [total] = 1 / 1.0905 X 100 = 91.70 %
