Answer: Option (A) is the correct answer.
Explanation:
Condensation is defined as the process in which vapors or gaseous phase changes into liquid phase.
Freezing is the process in which liquid phase changes into solid phase.
Evaporation is the process in which liquid phase changes into vapors or gaseous phase.
Melting is the process in which solid phase changes into liquid phase.
Therefore, we can conclude that names for given phase changes A and B is that A is condensation and B is freezing.
Answer : The temperature in degree Celsius is, 
Explanation :
The conversion used for the temperature from Kelvin to degree Celsius is:

where,
= temperature in Kelvin
= temperature in centigrade
As we are given the temperature in Kelvin is, 2.7
Now we have to determine the temperature in Kelvin.



Therefore, the temperature in degree Celsius is, 
Answer:
T₂ = 43.46 °C
Explanation:
Given that:
The heat of the formation of carbon dioxide = - 393.5 kJ/mol (Negative sign suggests heat loss)
It means that energy released when 1 mole of carbon undergoes combustion = 393.5 kJ = 393500 J
Heat gain by water = Heat lost by the reaction
Thus,
For water:
Mass of water = 5100 g
Specific heat of water = 4.18 J/g°C
T₁ = 25 °C
T₂ = ?
Q = 393500 J
So,
T₂ = 43.46 °C