Entropy change when heat flows
Grade 11 Science Worksheet - Challenge Me
Circle the best answer, or write your answer on the line.
50 g of ice melts at 273 K. What is its entropy change, to 0.01 J/K, Esme? Use L_f = 335,000 J/kg.
20 g of ice melts at 273 K. What is its entropy change, to 0.01 J/K, Jun? Use L_f = 335,000 J/kg.
100 g of ice melts at 273 K. What is its entropy change, to 0.01 J/K, Kira? Use L_f = 335,000 J/kg.
A student says entropy can never go down anywhere. Which reply fits OpenStax, Luz?
- Yes; no object's entropy can ever fall
- No; one part can lose entropy if another gains more
- Yes; even a freezer's inside cannot lose entropy
A student says heat could flow from a cold block to a hot one on its own, since energy is conserved. Which reply fits the second law, Milo?
- Yes; energy is conserved, so either way works
- No; that would lower the total entropy
- Yes; the entropy changes would cancel
A student says the hot side's entropy loss cancels the cold side's gain. Which reply fits ΔS = Q ÷ T, Noah?
- No; neither side's entropy can change, since entropy can't go down
- Yes; the same heat gives equal and opposite changes
- No; the cold side gains more, since its T is lower
Two blocks touch: one at 400 K, one at 300 K. Which way does heat flow on its own, Pia?
- From the 400 K block to the 300 K block
- From the 300 K block to the 400 K block
- Either way, since energy is conserved
Why do two blocks at different temperatures end at one shared temperature, Tala?
- Heat flows cold to hot until both match
- Heat flows hot to cold until the total entropy stops rising
- Each block's entropy stays fixed
What is the total entropy change of a complete reversible cycle, by Zee's reading (OpenStax)?
- Zero
- A large increase
- A large decrease
A hot block cools in a room. Is that process reversible, Ari?
- Yes; the total entropy stays zero
- No; it raises the universe's entropy
- Yes; the block's entropy falls, so the total falls