Oxygen is used up and glucose is broken down.
Answer: 1709.4 Joules
Explanation:
The quantity of Heat Energy (Q) released on cooling a heated substance depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)
Thus, Q = MCΦ
Since Q = ?
M = 18.5 grams
Recall that the specific heat capacity of copper C = 0.385 J/g.C
Φ = 285°C - 45°C = 240°C
Then, Q = MCΦ
Q = 18.5grams x 0.385 J/g.C x 240°C
Q = 1709.4 Joules
Thus, 1709.4 Joules is released when copper is cooled.
Answer:
P and V: inversely proportional
P and T: directly proportional
V and T: inversely proportional
Explanation:
For pressure and volume, as the volume goes up, meaning the container gets bigger, the pressure would go down. There would be more room in the container, so there would be less collisions between the molecules themselves and between the molecules and the container. This makes them inversely proportional.
For pressure and temperature, as the pressure goes up, there are more collisions, so the particles move faster. Temperature is the speed of the particles, so, since both pressure and temperature would go up at the same time, they are directly proportional.
For volume and temperature, this is similar to the PV relationship. As volume increases, there are less collisions between the particles. This means that the particles are going to move slower. Therefore, as volume goes up, temperature goes down, so they are inversely proportional.
Sorry this is super long, but I hope it fully explains the question for you! ☺
<h3>
Answer:</h3>
20.62 Kilo-joules
<h3>
Explanation:</h3>
- The Enthalpy of combustion of ethyl alcohol is -950 kJ/mol.
- This means that 1 mole of ethyl alcohol evolves a quantity of heat of 950 Joules when burned.
Molar mass of ethyl ethanol = 46.08 g/mol
Therefore;
46.08 g of C₂H₅OH evolves heat equivalent to 950 kilojoules
We can calculate the amount of heat evolved by 1 g of C₂H₅OH
Heat evolved by 1 g of C₂H₅OH = Molar enthalpy of combustion ÷ Molar mass
= 950 kJ/mol ÷ 46.08 g/mol
= 20.62 Kj/g
Therefore, a gram of C₂H₅OH will evolve 20.62 kilo-joules of heat
