Evaporation from the surface of a given liquid takes place more rapidly when
- A.the temperature is high and the surface area of the liquid is large
- B.the temperature is low and the surface area of the liquid is large
- C.the temperature is low and the surface area of the liquid is small
- D.the temperature is high and the surface area of the liquid is small
Correct answer
Explanation
The correct answer is A, the temperature is high and the surface area of the liquid is large. Both changes let more molecules escape from the surface each second.
Evaporation is a surface process: only molecules at the surface with enough energy break away into the air. A higher temperature gives more molecules that extra kinetic energy, and a larger surface area exposes more molecules to the air at once. The rate also rises with wind speed and falls as humidity rises. This is why wet clothes dry faster when spread out on a hot, windy day, and why tea in a saucer cools faster than in a cup.
B is wrong: a large surface helps, but a low temperature slows evaporation.
C is wrong: low temperature and small area both slow the process, so this is the slowest case.
D is wrong: high temperature helps, but a small surface limits how many molecules can escape.
Exam tip: evaporation rises with temperature, surface area and wind speed, and falls with humidity.
Practice Questions
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- A.haploid zygote
- B.diploid zygote
- C.non-motile male gametes
- D.motile male gametes
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Syngamy is the fusion of a male and a female gamete, and since each gamete is haploid, their union gives a diploid zygote.
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- A.One
- B.Two
- C.Three
- D.Four
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Read the full explanation →Which one of the following is the value of one nanometer?
- A.10⁻⁷ cm
- B.10⁻⁶ cm
- C.10⁻⁴ cm
- D.10⁻³ cm
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Read the full explanation →Which of the following is the general formula for saturated hydrocarbons?
- A.CₙH₂ₙ₊₂
- B.CₙH₂ₙ₋₂
- C.CₙH₂ₙ₊₁
- D.CₙH₂ₙ₋₁
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Read the full explanation →Which one of the following is not an epidemic disease?
- A.Cholera
- B.Malaria
- C.Smallpox
- D.Elephantiasis
Show answer
Elephantiasis, or lymphatic filariasis, is an endemic disease: it stays steadily present in certain regions and develops slowly over years, rather than breaking out suddenly in a large number of people.
Read the full explanation →