posted by Fabiola on .
when pressure decreases what happens with the boiling point, it decreases, increases or stays the same? I read the book (the example used is water) were it says that if vapor pressure is less than the pressure pushing down on the surface the bubbles formed collapse; but when vapor pressure equals atmospheric pressure the bubbles get bigger and so boiling occurs. I havent been able to figured out the answer, can you please help me?
and please explain me why is that the answer.
Another question about boiling point, does salt water has a higher boiling point than water?
and the last one
How can I figured out which formula has the greates pH, for example if I get NaOH. How would I know this is the one that has the highest pH?
thanks in advance
1. So doesn't that mean that if the atmospheric pressure becomes less, then the vapor pressure must be less to boil, which means the boiling point will be _________?
2. I don't know quite how to answer this because I don't know your grade level. Let's try this.
Delta T = Kb m
where delta T is the boiling point elevation, Kb is the boiling point constant, and m is the molality of the solution. What this means is that if a non-volatile solute is dissolved in the water,(NaCl, sugar, etc), the boiling point will be higher.
3. The correct answer is that you can't unless the question is asked correctly. What this means is that given an acid such as HCl and a base such as NaOH you can correctly answer that NaOH will have the higher pH. Remember that numbers less than 7 are acid, 7 is neutral, and numbers greater than 7 are basic. Given NH3 (a WEAK base) and NaOH (a STRONG base) of equal concentrations, we can correctly answer that NaOH has a higher pH. But given a solution of Ba(OH)2 and Sr(OH)2 with no indication of the strength of each base, we can't say which has the higher pH.