Question

How long would it take for 1.50 mol of water at 100.0 âc to be converted completely into steam if heat were added at a constant rate of 20.0 j/s ? express your answer to three significant figures and include the appropriate units?

Answer 1

To convert boiling water to steam, that would involve heat of vaporization. The heat of vaporization for water at atmospheric conditions is: ΔHvap = 2260 J/g.

Molar mass of water = 18 g/mol

Q = mΔHvap = (1.50 mol water)(18 g/mol)(2260 J/g) = 61,020 J

Time = Q/Rate = (61,020 J)(1 s/20 J) = 3051 seconds

In order to express the answer in three significant units, let's convert that to minutes.
Time = 3051 s * 1min/30 s = 102 min