Answer: Option (c) is the correct answer.
Explanation:
Entropy is defined as the degree of randomness. This means that more is the number of collisions taking place between atoms of a substance more will be the randomness.
Therefore, more will be the entropy of substance. We cannot measure the entropy but we can measure the change in entropy of a substance.
A thermometer is a glass tube that contains a liquid column generally mercury, and it is usually used to measure the temperature of human body.
A calorimeter is a device or apparatus that is used in a chemical reaction to measure the amount of heat involved.
Therefore, we can conclude that the student can't measure entropy directly, only an entropy change.
1.679 × 10²³ g of PbO₂ is present in 4.23×10⁴⁴ particles of PbO₂.
<u>Explanation:</u>
First the number of particles is converted into moles by dividing it by the Avogadro's number and then moles multiplied by the molar mass, we will get the mass of PbO₂ in grams.
4.23×10⁴⁴/ 6.022×10²³ = 7.02×10²⁰ moles
Now we have to multiply this by the molar mass of PbO₂, that is 239.2 g/mol, we will get the mass in grams.
7.02×10²⁰ moles × 239.2 g/mol = 1.679 × 10²³ g of PbO₂
Answer:
A; 
Explanation:
The best way to start solving this problem is to start with the molecule with the most atoms. Since there are 12 carbons on the left, you need 12 on the right so 12 would need to be placed in front of carbon dioxide. Also you need 22 hydrogens and in each molecule of water, there are two hydrogen molecules so you need 11 molecules of water. After balancing you find that you need 24 oxygen on the left so you place the coeffecient 12 in front of the oxygen molecule.
No :) They see different parts but I am a little confuse when you say the same part ;P
Explanation:
If water is ice-form, only the gap between molecules reduces but the molecule remains the same. The gap between liquid water molecules is greater than that between the molecules. That's why ice is thinner than water.
The intermolecular gap now increases in the gaseous form, which makes it less heavier than solid ice and liquid water. However, the molecule still remain the same.
