Answer:
The final temperature will be close to 20°C
Explanation:
First of all, the resulting temperature of the mix can't be higher than the hot substance's (80°C) or lower than the cold one's (20°C). So options d) and e) are imposible.
Now, due to the high heat capacity of water (4,1813 J/mol*K) it can absorb a huge amount of heat without having a great increment in its temperature. On the other hand, copper have a small heat capacity (0,385 J/mol*K)in comparison.
In conclusion, the copper will release its heat decreasing importantly its temperature and the water will absorb that heat resulting in a small increment of temperature. So the final temperature will be close to 20°C
<u>This analysis can be done because we have equal masses of both substances. </u>
Cu since the oxidation number of Cu is changed from 0 to +2. It means it is oxidized as per loss of two electrons.
Answer: 48,501 J/mol
Explanation:
1) Action barrier = activation energy = Ea
2) Data:
i) T₁ = 12°C = 12 + 273.15 K = 285.15K
ii) T₂ = 22°C = 22 + 273.15 K = 295.15 K
iii) rate constant = k: k₂ / k₁ = 2
iv) Ea = ?
3) Formula:
Arrhenius' law gives the relationship between the constant of reaction and the temperature:

4) Solution
By arranging the formula, you get:
㏑[k₂/k₁] =Ea/R [1/T₁ - 1/T₂]
Replace k₂ = 2k₁; T₁ = 285.15; and T₂ = 295.15
ln[2] = Ea/8.314 J/K mol × [1/285.15 - 1/295.15]K
Ea = ln [2] × 8.314 J/K mol / [1.18818×10⁻⁴K] = 48,501 J/mol
The energy released in a nuclear reaction may appear only in one of these three ways Kinetic energy of the products. The emission of gamma rays. And gamma rays are emitted by unstable nuclei in their own transition that is from a high energy state that than goes to a lower energy state that is properly known as gamma decay.