View Full Version : Density
brijmohan123456
Jun 17, 2012, 08:51 AM
Sir,I am asking this question in preference to my last question.After reading the reply of my last question I have come to a conclusion that the weight of water vapour at gasseous state is 22.4 kg as then only the volume of water at gasseous state will be 22,4 litre if it's density will be 1g/cc.Am I right? Or the density of water at gasseous state is different than 1g/cc.sir,whatever is the reason please give me a detailed explanation or you can also provide me a website through which I will be able to make my concept clear.Sir please help me as my exam are starting soon.
Thank you
DrBob1
Jun 18, 2012, 06:31 AM
sir,I am asking this question in preference to my last question.After reading the reply of my last question I have come to a conclusion that the weight of water vapour at gasseous state is 22.4 kg as then only the volume of water at gasseous state will be 22,4 litre if it's density will be 1g/cc.Am I right ?.Or the density of water at gasseous state is different than 1g/cc.sir,whatever is the reason please give me a detailed explaination or you can also provide me a website through which I will be able to make my concept clear.Sir please help me as my exam are starting soon.
Thank you
A gas has a MUCH lower density than does a liquid.
Picture two balloons - one filled with water, one blown up with air. The water filled balloon is much heavier, correct? The balloon filled with air will weigh almost twice as much as one filled with water vapor.
This is common sense, think aobut it.
ebaines
Jun 18, 2012, 08:41 AM
Just to add: the mass of liquid water and water vapor corresponsing to one mole is 18 grams. That number doesn't change no matter whether the water is in solid, liquid, or vapor form. But the volume of one mole of water does depend on the state it is in: 1 mole of liquid water occupies 18 cm^3, whereas one mole of water vapor at standard temperature and pressure occupies 22.4L of volume. Thus the density of water vapor is much much less than the density of liquid water. The reason is that as a liquid the individual water molecules are packed so close together that they touch each other, whereas in gaseous form the individual molecules bouce of each other and maintain an average separation distance that is much larger. Thus there are fewer molecules of water vapor per cm^3 than there are of liquid water per cm^3.