Question 1: Specific heat capacity is the amount of heat energy required to raise the temperature of 1 kilogram of a substance by 1 degree Celsius (or Kelvin). It is a measure of how much energy a material can store and is expressed in joules per kilogram per degree Celsius (J/kg°C).

Answer: It is the amount of heat needed to raise 1 kg of a substance by 1°C or 1 K.

Question 1: Explain why metals generally have a lower specific heat capacity compared to water.

Answer: Metals have a lower specific heat capacity because their electrons and atoms require less energy to increase in temperature compared to water, which has strong hydrogen bonds.

Question 2: Calculate the heat energy needed to raise the temperature of 3 kg of aluminium from 20°C to 80°C. The specific heat capacity of aluminium is 900 J/kg°C.

Answer: Q = mcΔT = 3 kg × 900 J/kg°C × (80°C - 20°C) = 3 × 900 × 60 = 162,000 J

Question 3: Write the formula used to calculate the heat energy transferred when heating a substance. Include units in your explanation.

Answer: Q = mcΔT, where Q is heat energy in joules (J), m is mass in kilograms (kg), c is specific heat capacity in J/kg°C, and ΔT is temperature change in °C.

Question 4: Describe an experiment to determine the specific heat capacity of a metal sample. Mention key variables and safety precautions.

Answer: An experiment involves heating a metal sample in a controlled environment, measuring its initial temperature, then immersing it in water of known temperature and recording the final temperature. The variables include mass of the metal, initial temperatures, and heat transfer. Safety precautions include handling hot objects with tongs and wearing safety goggles to prevent burns.

Question 5: A 2 kg block of copper is heated from 25°C to 75°C. The heat energy supplied is 20,000 J. Calculate the specific heat capacity of copper.

Answer: c = Q / (m × ΔT) = 20000 J / (2 kg × (75°C - 25°C)) = 20000 / (2 × 50) = 20000 / 100 = 200 J/kg°C

Question 6: Which of the following materials generally has the highest specific heat capacity? A) Aluminium B) Copper C) Water D) Iron

Answer: C) Water

Question 7: Fill in the blank: The specific heat capacity of a substance determines how much ___________ energy is needed to change its temperature.

Answer: thermal

Question 8: A 5 kg object is heated, requiring 25,000 J of energy to raise its temperature by 10°C. What is its specific heat capacity?

Answer: c = Q / (m × ΔT) = 25000 J / (5 kg × 10°C) = 25000 / 50 = 500 J/kg°C

Question 9: Explain why the specific heat capacity of water is important in regulating Earth's climate.

Answer: Water has a high specific heat capacity, meaning it can absorb and store large amounts of heat with little change in temperature. This property helps regulate Earth's climate by buffering temperature fluctuations in oceans and atmosphere, contributing to climate stability.