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. 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.

The boiling point of water at Mount Everest = 72 ° C The boiling point of water at Burj Khalifa = 97 ° C Therefore, Change in boiling point from Everest to Burj Khalifa is 97 - 72 = 25 ° C . Percentage increase in boiling point of water = 25 72 × 100 = 34 . 7 %

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. Will it take less time to cook pasta at the top Burj Khalifa or the summit of Everest? Explain your answer. What do you except to happen to the boiling point below sea level?

The boiling point of water at Mount Everest = 72 ° C The boiling point of water at Burj Khalifa = 97 ° C As the altitude increases, the pressure decreases, or we can also say temperature decreases. Hence, it will take less time to cook pasta at the summit of Mount Everest, as the temperature of boiling water is less than Burj Khalifa. Water will boil at a temperature greater than 100 ° C below sea level, as the pressure increases.

When a solid substance changes into gaseous state without forming liquid is known as sublimation. This is an endothermic process. When the process reversed, it is known as deposition. ∆ H sublimation = - ∆ H deposition

E M B I B E

MYP Chemistry A concept-based approach Years 4&5>Chapter 6 - Form>Exercise 6>Q 1

HARD

MYP:4-5

IMPORTANT

Earn 100

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 $+ 23$ $+ 871$

Important Questions on Form

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.

HARD

MYP:4-5

IMPORTANT

MYP Chemistry A concept-based approach Years 4&5>Chapter 6 - Form>Data-based question: Cooking at altitude>Q 2

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

Will it take less time to cook pasta at the top Burj Khalifa or the summit of Everest? Explain your answer. What do you except to happen to the boiling point below sea level?

HARD

MYP:4-5

IMPORTANT

MYP Chemistry A concept-based approach Years 4&5>Chapter 6 - Form>Exercise 8>Q 1

Explain how the role of energy differs between condensation and evaporation.

MEDIUM

MYP:4-5

IMPORTANT

MYP Chemistry A concept-based approach Years 4&5>Chapter 6 - Form>Exercise 8>Q 1

What is sublimation?