Answer : The enthalpy change during the reaction is -6.48 kJ/mole
Explanation :
First we have to calculate the heat gained by the reaction.
where,
q = heat gained = ?
m = mass of water = 100 g
c = specific heat =
= final temperature =
= initial temperature =
Now put all the given values in the above formula, we get:
Now we have to calculate the enthalpy change during the reaction.
where,
= enthalpy change = ?
q = heat gained = 23.4 kJ
n = number of moles barium chloride =
Therefore, the enthalpy change during the reaction is -6.48 kJ/mole
Answer:
e. H₂O
Explanation:
The specific heat capacity is defined as the amount of heat required to raise the temperature of the substance in 1 unit. If you have to warm your room, you have to choose the substance with the <u>highest</u> specific heat capacity value. This substance will retain the highest amount of heat. From the options, the highest value is 4.184 J/g°C (water, H₂O). Thus, 1 gram of water will retain 4.184 J when the temperature is raised to 1°C. That is a higher amount of heat in comparison with, for example, granite, which is able to retain 0.79 J per gram when the temperature is raised to 1°C.
However, you have to consider that the boiling point of water is 100°C, so the temperature at which you have to warm the room is the temperature at which water will be passing to the gas state.