Answer:
These reactions can be categorized as spontaneous and non spontaneous
Step-by-step explanation:
thus i. Glucose breaks down in our bodies to provide energy. This exergonic reaction is spontaneous to liberate heat,The free energy for the reaction is negative.
A lump of sugar dissolves in a cup of coffee- this is another forms of spontaneous reaction where bond breaking is informed. Since bond breaking involves loss of heat energy, this is another forms of Spontaneous reaction..
iii. A candle burns- heat is liberated to the surrounding environments as wax melts .This is a spontaneous reaction as the Oxygen in the surrounding air mixed with wax to give out flame on combustion and liberate heat,given CO2 and water as waste products.
Ice cream melts on a hot day- when ice melts on a hot day, heat energy from the sunlight is used to melt the hydrogen bonds between the molecules of water together, the breaking of bonds is a spontaneous reaction.
v. Food is refrigerated in a refrigerator. This is bond formation, and therefore non spontaneous. Rather energy is drawn in to form hydrogen bonds to freeze or hold the food molecules together. Refrigeration expels heat from the food substances, cooling it , by drawing in energy for bond formation.
A drop of food coloring spreads in a glass of water- this is a spontaneous reaction as bonds holding the molecules that made up the coloring are broken down so that these molecule could gain energy to disperse in water. therefore it is an example of spontaneous reaction