MEDIUM
MYP:4-5
IMPORTANT
Earn 100

Why is the density of ice lower than that of liquid water? Give an example of where this can be observed on our planet.

Important Questions on Form

HARD
MYP:4-5
IMPORTANT
MYP Chemistry A concept-based approach Years 4&5>Chapter 6 - Form>Exercise 4>Q 1
How much energy does it take to melt 1.5 kg of water that is at its melting point?
HARD
MYP:4-5
IMPORTANT
MYP Chemistry A concept-based approach Years 4&5>Chapter 6 - Form>Exercise 4>Q 1
How much energy does it take to melt 1.5 kg of lead that is at its melting point?
HARD
MYP:4-5
IMPORTANT
MYP Chemistry A concept-based approach Years 4&5>Chapter 6 - Form>Exercise 6>Q 1

Compare these values of enthalpies of fusion and vaporization. Explain why the enthalpy of vaporization for a substance is greater than its enthalpy of fusion.

  Enthalpy of fusion (Jg-1) Enthalpy of vaporization (Jg-1)
Water +334 +2.260
Carbon dioxide +184 +574
Lead +23 +871

 

MEDIUM
MYP:4-5
IMPORTANT
MYP Chemistry A concept-based approach Years 4&5>Chapter 6 - Form>Exercise 6>Q 2
Explain why the temperature of a boiling liquid does not continue to increases above its boiling point.
MEDIUM
MYP:4-5
IMPORTANT
MYP Chemistry A concept-based approach Years 4&5>Chapter 6 - Form>Exercise 6>Q 3
Steam burns are regarded as being far more harmful than a burn from boiling water. What changes of state is occurring when steam reaches your skin? Why are the burns severe? Explain this in terms of energy transfer.
MEDIUM
MYP:4-5
IMPORTANT
MYP Chemistry A concept-based approach Years 4&5>Chapter 6 - Form>Exercise 6>Q 4
Explain why your skin feels cold when you leave the water after swimming on a hot summer day.
MEDIUM
MYP:4-5
IMPORTANT
MYP Chemistry A concept-based approach Years 4&5>Chapter 6 - Form>Exercise 6>Q 5
Why does boiling liquid immediately stop boiling the moment you remove the source of energy?
HARD
MYP:4-5
IMPORTANT
MYP Chemistry A concept-based approach Years 4&5>Chapter 6 - Form>Data-based question: Cooking at altitude>Q 1

The boiling point of water is 100°C at an atmospheric pressure of 1 atmosphere or 100 kPa, a typical level at sea level. At higher altitudes the air pressure decreases and the boiling point increases.

Question Image

Study the graph and the table above. Use the information to calculate the percentage increase of the boiling point from the summit of Everest to the top of the Burj Khalifa.