Answer:
Electromotive force or e.m.f is defined as the battery's energy per Coulomb of charge passing through it. like other measures of energy per charge emf has SI unit of volts , equivalent to joules per coulomb.
Explanation:
Let us assume that the given data is as follows.
V = 3.10 L, T =
= (19 + 273)K = 292 K
P = 40 torr (1 atm = 760 torr)
So, P = 
= 0.053 atm
n = ?
According to the ideal gas equation, PV = nRT.
Putting the given values into the above equation to calculate the value of n as follows.
PV = nRT

0.1643 = 
n = 
It is known that molar mass of ethanol is 46 g/mol. Hence, calculate its mass as follows.
No. of moles =
mass =
g
= 0.315 g
Thus, we can conclude that the mass of liquid ethanol is 0.315 g.
<span>The mass of an object is measured in either grams or kilograms. Mass is best described as the amount of matter, or "stuff," in a solid, and is different from weight (which is the force of gravity on an object). Since mass is used with solids, it will be measured in grams or kilograms (rather than in something like liters, which would be used with the volume of a liquid). To measure mass, you can use a balance, for example a triple balance beam.</span>