If a gas pressure gauge reads 15 mm Hg, what is the pressure in atmospheres?

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Answer 1 · 2017-06-12T02:33:13

0,020 atmospheres

760 mm Hg = 1 atmosphere.

# 15/760 = atmosphere#

# 15/760 = 0.0197368 atmospheres rounding off to 2 significant digits gives

0.020 atmospheres

Answer 2 · 2017-06-12T02:35:19

#0.020# #"atm"#

To convert between millimeters Mercury (#"mm Hg"#) and atmospheres (#"atm"#), we use the conversion factor

#(1"atm")/(760"mm Hg")#

That is, #1# atmosphere equals #760# millimeters Mercury.

Using dimensional analysis, we can convert the given pressure:

#15# #cancel("mm Hg")((1"atm")/(760cancel("mm Hg"))) = color(red)(0.020# #color(red)("atm"#

#15# #"mm Hg"# is equal to #0.020# #"atm"#, rounded to #color(blue)(2# significant figures, the amount given in the problem.