Final answer:
Using the specific heat capacity of ice, the final temperature of 2 grams of ice after adding 10 calories of energy at an initial temperature of -30°C is calculated to be -20°C.
Step-by-step explanation:
To calculate the final temperature of 2 grams of ice when 10 calories of energy are added to it at an initial temperature of -30°C, we need to use the specific heat capacity of ice. The specific heat capacity of ice is approximately 0.5 cal/g°C. The formula to calculate the heat absorbed is Q = mcΔT, where Q is the heat added, m is the mass of the ice, c is the specific heat capacity, and ΔT is the change in temperature.
Using the provided information: Q = 10 cal, m = 2 g, c = 0.5 cal/g°C, we get:
10 cal = 2 g × 0.5 cal/g°C × ΔT ⇒ ΔT = 10 cal / (2 g × 0.5 cal/g°C) ⇒ ΔT = 10 cal / 1 cal/g°C ⇒ ΔT = 10°C.
Since the ice is initially at -30°C and it absorbs enough heat to change the temperature by 10°C, the final temperature of the ice will be -30°C + 10°C = -20°C.
Therefore, the correct answer is A. -20°C.