At standard atmospheric pressure, water boils at 100 degrees Celsius. However, on the summit of Mount Everest, the atmospheric pressure is much lower than standard atmospheric pressure. What is the effect of this lower pressure on the phase diagram of water?

Question

BlackTom AI · Accepted Answer

Consider the scenario: a lower atmospheric pressure at the summit of Mount Everest affects water's phase behavior. 
Option a: 'The boiling point of water will decrease, and it will take less time for water to boil.' This aligns with the Clapeyron behavior on a P-T diagram: at lower external pressure, water reaches its boiling state at a lower temperature, so boiling begins sooner when heat is applied, and thus it can boil with less energy input than at 1 atm; the phrase 'take less time' is somewhat context-dependent but is reasonable under a fixed heat input as the temperature required is lower. 
Option b: 'The boiling point of water will remain the same, but it will take longer for water to boil.' The boiling point is not invariant to pressure; at lower pressure, the boiling point decreases, so this statement is incorrect because the temperature threshold changes. Also, boiling typically occurs more readily, not more slowly, when pressure is reduced, given comparable heating, so the time aspect is not supported. 
Option c: 'The boiling point of water will remain the same, but it will take less time for water to boil.' Again, the boiling point is not invariant with pressure; lowering external pressure lowers the boiling temperature, so claiming the boiling point remains the same is incorrect. The 'less time' claim could be argued in some setups, but it contradicts the fundamental pressure–temperature relationship for phase change. 
Option d: 'The boiling point of water will increase, and it will take longer for water to boil.' This directly conflicts with known thermodynamics: reducing ambient pressure lowers the boiling point, not raises it; claiming an increased boiling point would require higher external pressure or different constraints, so this choice is incorrect. 
In summary, the core concept is that vapor pressure equals ambient pressure at the boiling point; at Everest’s lower pressure, water reaches vapor equilibrium at a lower temperature, so boiling begins at a lower temperature than 100°C. This makes option a the best description among the given statements, while options b, c, and d misstate the fundamental pressure–temperature relationship of boiling.

PHAS0006_24-25 Week 3 Quiz

At standard atmospheric pressure, water boils at 100 degrees Celsius. However, on the summit of Mount Everest, the atmospheric pressure is much lower than standard atmospheric pressure. What is the effect of this lower pressure on the phase diagram of water?

查看解析

登录即可查看完整答案

类似问题

On the phase diagram below the triple point is (1) , the critical point is (2) , and the line representing melting is (3) .

Use the phase diagram to answer the following question: Which state of matter is the most stable for water at 75oC under 2kPa of pressure?

In a consumer society, many adults channel creativity into buying things

Economic stress and unpredictable times have resulted in a booming industry for self-help products

People born without creativity never can develop it

A product has a selling price of $20, a contribution margin ratio of 40% and fixed cost of $120,000. To make a profit of $30,000. The number of units that must be sold is: Type the number without $ and a comma. Eg: 20000

Which of the following statement regarding cost is correct:

更多留学生实用工具

考试浏览器助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单