Passage I
When a substance dissolves in H2O, heat is either absorbed from or given off to the solution. “Experiments were done in which a known mass of a solute was added to a known mass of H2O at a known initial temperature (Ti) in a closed, insulated container. When the maximum 'temperature change of the solution had occurred, the final temperature (Tf) was recorded. The maximum temperature change (△T) was then calculated as follows:
△T = Tf - Ti
Figures 1 and 2 show the results for lithium chloride (LiCl) and ammonium nitrate (NH4NO3), respectively. In each trial, all of the solute completely dissolved.
4. According to Figure 2, when 5 g of NH4NO3 was added to 100 g of H2O, the temperature of the solution:
Your Answer is
Correct Answer is G
Explanation
Observing figure 2, it is found that after adding 5g NH4NO3 to 100 g water, the temperature drops, that is, ΔT is a negative number