For a particular reaction, Δ H ∘ = 20.1 kJ/mol and Δ S ∘ = 45.9 J / (mol ⋅ K). Assuming these values change very little with temperature,
at what temperature does the reaction change from nonspontaneous to spontaneous in the forward direction? T = K

438 K

Explanation:

According to Gibbs equation:

= Gibb's free energy change

= enthalpy change = 20.1 kJ/mol = 20100 J/mol

T = temperature

= entropy change = 45.9 J/Kmol

A reaction is at equilibrium when = Gibb's free energy change is zero and becomes spontaneous when = Gibb's free energy change is negative.

T=437.9K

Thus the temperature at which the reaction change from nonspontaneous to spontaneous in the forward direction is 438 K

both adhesion and cohesion are attractions.

they are different in that adhesion is the force of attraction between the molecules of two different substances, whereas cohesion is the force of attraction between molecules of the same substance.

possible examples include capillary action, in which the adhesion between water and glass causes the water to rise in a narrow tube against the force of gravity.

because of hydrogen bonding, water is extremely cohesive.

this causes molecules on the surface of water to be drawn inward, which is why drops of water form beads on smooth surfaces.

hope this .

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.