Which colligative property is employed when salt is put on an icy sidewalk to melt ice?

vapor-pressure lowering

boiling-point elevation

freezing-point depression

For this number, we are to determine the colligative property that is affected by the addition of salt in the sidewalk in order to melt the ice. The answer is that the colligative property being displayed is the freezing point depression. Colligative properties are innate properties of substances and are only dependent on the amount of substance being added.

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant.