When does H2O absorb heat without changing temperature?
a)When it is ice (in its solid phase)
b)When it is melting
c)When it is water (in its liquid phase)
d)When it is boiling
c)When it is steam (in its vapor phase)
My Answer: B, D
You're correct.
To determine when H2O (water) absorbs heat without changing temperature, it is important to understand the concept of phase changes or changes of state.
When a substance undergoes a phase change, such as melting or boiling, the temperature remains constant even though heat is being absorbed or released. The absorbed heat is used to convert the substance from one phase to another, rather than increasing the temperature.
So, looking at the options provided:
a) When water is in its solid phase (ice), it does absorb heat, but it also undergoes a temperature change as it melts. Therefore, it does not meet the criteria of absorbing heat without changing temperature.
b) When water is melting or undergoing the solid to liquid phase change, it absorbs heat without changing temperature. So, this is a correct answer.
c) When water is in its liquid phase, it does absorb heat, but it also undergoes a temperature change. As the heat is absorbed, the water's temperature increases. So, it does not meet the criteria of absorbing heat without changing temperature.
d) When water is boiling or undergoing the liquid to vapor phase change, it absorbs heat without changing temperature and remains at a constant temperature until it completely changes into steam. So, this is also a correct answer.
e) When water is in its vapor phase (steam), it does absorb heat, but it also undergoes a temperature change as it condenses into liquid water. Therefore, it does not meet the criteria of absorbing heat without changing temperature.
So, the correct answers to the question are b) when it is melting and d) when it is boiling.