Question

which of the following is NOT a spontaneous process

a. the combustion of natural gas in your kitchen after ignition

b. a glass of water you left in your apartment vaporized to air

c. a bike going up a hill by itself

d. a hot drink cooling down to room temperature

e. ammonia dissolved in water absorbing heat from the surrounding environment

Answer 1

Spontanoeus reactions are those reactions which are exothermic i.e. they release energy to the surroundings or the ereactions which do not require any external energy to occur.

a. During combustion heat is released to the surrounding. Thsu, it is spontaneous.

b. Glass of water takes heat from the surrounding to get vapourized. Thus, it is non spontaneous process.

c. A bike requires energy to go up a hill. Thus, it is non spontaneous process.

d. Hot drink releases energy to the surrounding while cooling down. Thus, it is spontaneous process.

e. The system absorbs heat from the surrounding. Thsi it is non spontaneous process.