Question

q.22. the table shows the melting points and boiling points for different substances. identify the state of given substances at room temperature (room temperature is around 20°c).

Explanation:

Step1: Determine the state of water

• Melting point of water is \(0^{\circ}C\) and boiling point is \(100^{\circ}C\).
• Room temperature \(20^{\circ}C\) is between melting and boiling point. So, water is liquid.

Step2: Determine the state of oxygen

• Melting point of oxygen is \(- 218^{\circ}C\) and boiling point is \(-183^{\circ}C\).
• Room temperature \(20^{\circ}C\) is above boiling point. So, oxygen is gas.

Step3: Determine the state of iron

• Melting point of iron is \(1538^{\circ}C\) and boiling point is \(2861^{\circ}C\).
• Room temperature \(20^{\circ}C\) is below melting point. So, iron is solid.

Step4: Determine the state of sulfuric acid

• Melting point of sulfuric acid is \(10.3^{\circ}C\) and boiling point is \(337^{\circ}C\).
• Room temperature \(20^{\circ}C\) is between melting and boiling point. So, sulfuric acid is liquid.

Step5: Determine the state of magnesium

• Melting point of magnesium is \(650^{\circ}C\) and boiling point is \(1090^{\circ}C\).
• Room temperature \(20^{\circ}C\) is below melting point. So, magnesium is solid.

Step6: Determine the state of nitrogen

• Melting point of nitrogen is \(-210^{\circ}C\) and boiling point is \(-195^{\circ}C\).
• Room temperature \(20^{\circ}C\) is above boiling point. So, nitrogen is gas.

Answer:

Substance	State at Room Temperature
Oxygen	Gas
Iron	Solid
Sulfuric acid	Liquid
Magnesium	Solid
Nitrogen	Gas