NY Regents Chemistry Exam June 2023: 55-57
During a laboratory activity, a student heats a beaker containing 120.0 grams of water as shown in the diagram below.
The table below shows the mass of the water and the temperature of the water before and after heating. During this laboratory activity, appropriate safety equipment is used and safety procedures are followed.
Data for Heating Water
Mass of 120.0 mL of water = 120.0 g
Temperature of water before heating = 23.0°C
Temperature of water after heating 20.0 min = 86.0°C
55 State the direction of heat flow between the candle flame and the beaker of water during the time the candle is lit.
Solution: Heat always flows from the hotter object to the cooler object. It will flow from from the candle flame to the beaker of water.
56 Show a numerical setup for calculating the amount of heat, in joules, absorbed by the water in the beaker as a result of the burning candle.
Solution: Table T on the Reference Table has the formula for calculating heat. q=mCΔT where q=heat, m=mass, C = specific heat capacity found in Table B, ΔT = Tfinal-Tinitial
q= (120.0 g)(4.18 J/g•K)(86.0°C-23.0°C)
57 State how the molecular motion of the water molecules in the beaker changes as the temperature increases.
Solution: As the temperature increases, the molecular motion of the water molecules will increase as well.