How much energy is required to raise the temperature of 74 g of water from 19 °C to 47 °C.
1 answer:
Answer:
The energy required is 8660.96 J.
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
Sensible heat is the amount of heat that a body absorbs or releases without any changes in its physical state (phase change). This heat is given by the expression:
Q = c * m * ΔT
where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.
In this case, you know:
- C= 4.18
- m= 74 g
- ΔT= Tfinal - Tinitial= 47 C - 19 C= 28 C
Replacing:
Q= 4.18 *74 g* 28 C
Solving:
Q= 8660.96 J
<u><em>The energy required is 8660.96 J.</em></u>
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Answer: Mass of water produced is 17.3 grams
Explanation:
To calculate the number of moles, we use the equation:
.....(1)
For benzene:
Given mass of benzene = 25.0 g
Molar mass of benzene= 78 g/mol
Putting values in equation 1, we get:
The chemical equation for the reaction follows:
As, oxygen is an excess reagent. Thus benzene is considered as a limiting reagent because it limits the formation of product.
By Stoichiometry of the reaction:
2 moles of benzene produces 6 moles of water
So, 0.32 moles of benzene will produce = of water
Now, calculating the mass of water from equation 1, we get:
Molar mass of water= 18 g/mol
Moles of water = 0.96moles
Putting values in equation 1, we get:
Thus mass of water produced is 17.3 grams