Pure water is found to boil at 155C. Why is this?

Question

i meant 115C

Answer 1

Where do you see that pure water boils at 155 C? Do you have a link to a page that says this?


I agree with Gebobs on this one. He is right. The water would boil at a higher temperature in a higher pressure.

Answer 2

mmmhhh....
that is weird, but here are some reasons why boiling point of water may change:
-ions or molecules present: they kind of disrupt the intramolecular forces of water...and less energy is needed to make the water boil, and more to make it freeze.
- atmospheric pressure. at higher altitude, less pressure...water takes more time to boil and the boiling point is reduced. For example, I lived in a place which was 3000 m above the sea level, and water boiling point was 93 C instead of 100C. Also, you can make water boil at room temperature, by putting it in a closed flask with an opening to a vacuum. The point is that you reduce the pressure, so the vapor pressure of water equals the pressure inside the flask. I hope this helps

Answer 3

There are two ways to raise the boiling point of water: 1) raise the presure or 2) add impurities. Since your sample is pure, the presure must be elevated. In this case I would say the pressure is about 2000 torr.

Answer 4

This would be the case at high pressure. At standard pressure, water boils at 100C.

According to the chart on the link below, the pressure would have to be about 110 psia (758 kPa) to increase the boiling point to 334F (~155C), about 7.5 times standard atmospheric pressure.