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>
Energy is required to change the phase of a material, with the change in energy either it decreases or increases.
When the phase is changed, the temperature and kinetic energy does not change it stays the same but the internal energy changes.
Internal energy is the sum of chemical potential energy and kinetic energy of the molecules, and when the internal energy changes during a phase change it means average potential energy is changing.
Answer:
True
Explanation:
Hydrogen bonding is a bond that exists between hydrogen and a highly electronegative element such as oxygen, nitrogen, fluorine etc.
The greater solubility of the triphenylphosphine oxide owes to the hydrogen bonded interaction between it and the 1-propanol.
The alkene lacks such hydrogen bonded interaction because it does not have a highly electronegative atom in its structure.
Hence, triphenylphosphine oxide is removed based on its polarity and hydrogen bonding ability.
Answer:
1.49 × 10⁹ years
Explanation:
Step 1: Calculate the rate constant (k) for the nuclear decay of U-235
The decay follows first-order kinetics with a half-life (t1/2) of 703 × 10⁶ years. We can calculate "k" using the following expression.
k = ln2/ t1/2 = ln2 / 703 × 10⁶ y = 9.86 × 10⁻¹⁰ y⁻¹
Step 2: Calculate the time elapsed (t) so that the final amount ([U]) is 23.0% of the initial amount ([U]₀)
For first order kinetics, we will use the following expression.
ln ([U]/[U]₀) = -k × t
ln (0.230[U]₀/[U]₀) = -9.86 × 10⁻¹⁰ y⁻¹ × t
ln 0.230 = -9.86 × 10⁻¹⁰ y⁻¹ × t
t = 1.49 × 10⁹ y
Answer: Darwin spent five years on his journey as the ship's naturalist on the H.M.S. Beagle. Some of the evidence he used to support his theory was based on fossils he saw in South America. In the 1800's, most people were of the belief that the world was only a few thousand years old and that organisms that existed were unchanged since the beginning. However, the fossil evidence that he found showed giant versions of modern animals that no longer existed. It pointed to the idea of an ancestor that may have changed over time to the modern life forms that exist today. He also noted that the most likely place that the life forms on the Galapagos Islands could have come from originally, was Equador which was about 600 miles away. Differences in environment, food supply, temperature, etc. would put different pressures on animals on each of the various islands. Over time, natural selection would favor those best adapted for their various environments and after two million years, you have many different species that have evolved from common ancestors in Equador. The most famous of course, are Darwin's finches. Also famous are the different giant tortoises that vary by shells, size and habits, from island to island. Other famous animals include iguanas. One is extremely unique, the marine iguana, which is the only marine iguana in the entire world.
Explanation:
