Indicate which of the following has the highest entropy at 298 K.

0.5 g of HCN
1 mol of HCN
2 kg of HCN
2 mol of HCN
All of the above have the same entropy at 298 K.

Change all of the answers to grams. The largest number of grams will have the largest S.

2 kg HCN

Well, you're about to witness the entertaining world of entropy! Buckle up and get ready for some laughter. Now, entropy is like a random party in thermodynamics. It measures the randomness or disorder in a system. So, let's see what's happening here.

First up, we have 0.5 grams of HCN. Hmm, that's like throwing a pebble into a pond. Not much chaos there.

Next, we have 1 mole of HCN. Now, that's more like it! Imagine a room bustling with 6.022 x 10^23 HCN molecules, all doing their merry dance. It's quite a lively party!

Then we have 2 kilograms of HCN. Oh boy, that's a ton of HCN! It's a full-blown festival! Think of fireworks, confetti, and a crowd of HCN molecules jiving to the beat. Can you feel the excitement?

And finally, we have 2 moles of HCN. Now, it's still a pretty happening event, but not as wild as the 2 kilogram party. Think of it as the afterparty, where things start winding down but people are still having a good time.

So, to answer your question, the system with the highest entropy at 298 K is 2 kilograms of HCN. It's the grandest party in town!

But hey, don't worry if you got confused in all the hoopla. In reality, all the options have different entropies, with the 2 kilogram party being the most disorderly. Keep the laughter flowing!

To determine which of the given substances has the highest entropy at 298 K, we need to understand the definition of entropy and how it depends on the amount of substance present.

Entropy is a measure of the disorder or randomness of a system. It is related to the number of microstates (possible arrangements of particles) that a system can have at a given energy level. Generally, the more microstates a system can have, the higher its entropy.

In this case, we are comparing different amounts of HCN (hydrogen cyanide). HCN is a molecular compound, so its entropy depends on the number of different ways its molecules can be arranged.

Now, let's analyze each option:

0.5 g of HCN: Since we have a specific mass, we need to consider the molar mass of HCN, which is approximately 27 g/mol. Using this information, we can calculate the number of moles of HCN:

0.5 g / 27 g/mol ≈ 0.0185 mol

1 mol of HCN: This option gives us exactly 1 mol of HCN.

2 kg of HCN: Again, we need to convert the mass to moles. The molar mass of HCN is still the same, so we can calculate the number of moles:

2000 g / 27 g/mol ≈ 74.07 mol

2 mol of HCN: This option gives us exactly 2 mol of HCN.

From the analysis above, we can conclude that 2 kg of HCN has the highest entropy at 298 K. The reason behind this is that the more moles of HCN we have, the greater the number of microstates, and thus the higher the entropy.

Therefore, the correct answer is 2 kg of HCN.