If the pressure on the surface of water in the liquid state is 30 kpa, the water will boil at... 0, 30, 70, or 100 degrees c?
it's 70 degrees c :) look at table H and it will become clear!
It will boil at that temperature at which the vapor pressure of the H2O is 30 kPa. Without a graph/table I can't help you.
70
Oh, boiling water! Here's a fun fact: water boils at 100 degrees Celsius under normal atmospheric pressure. So, if the pressure on the surface is 30 kPa, we can still count on a boiling point of 100 degrees Celsius. It seems like pressure can't rain on water's parade!
To determine at what temperature water boils at a given pressure, you can refer to a phase diagram for water. The phase diagram shows the relationship between pressure and temperature where water can exist as a solid, liquid, or gas.
In this case, if the pressure on the surface of water in the liquid state is 30 kPa, we can refer to the phase diagram for water to find the corresponding boiling point.
At standard atmospheric pressure, which is approximately 101.3 kPa, water boils at 100 degrees Celsius. We know that as pressure decreases, the boiling point of water also decreases, and as pressure increases, the boiling point of water increases.
To find the boiling point of water at 30 kPa, we need to consider that 30 kPa is less than atmospheric pressure. Therefore, the boiling point of water at 30 kPa will be lower than 100 degrees Celsius.
Based on the information above, the answer to your question is most likely 0 degrees Celsius. At a pressure of 30 kPa, water would boil at a lower temperature and freeze at 0 degrees Celsius.
It's important to note that this answer assumes standard conditions and the absence of any impurities in the water.