Answer:
100g / (5.2g/cm3)
= 100g / (5.2g / 1cm3)
= 100g x 1cm3 / 5.2 g
= 19.2 cm3
Since 1 cm3 = 1 ml, your answer is 19.2 ml.
Answer:
Option 3. The catalyst does not affect the enthalpy change (
) of a reaction.
Explanation:
As its name suggests, the enthalpy change of a reaction (
) is the difference between the enthalpy of the products and the reactants.
On the other hand, a catalyst speeds up a reaction because it provides an alternative reaction pathway from the reactants to the products.
In effect, a catalyst reduces the activation energy of the reaction in both directions. The reactants and products of the reaction won't change. As a result, the difference in their enthalpies won't change, either. That's the same as saying that the enthalpy change
of the reaction would stay the same.
Refer to an energy profile diagram. Enthalpy change of the reaction
measures the difference between the two horizontal sections. Indeed, the catalyst lowered the height of the peak. However, that did not change the height of each horizontal section or the difference between them. Hence, the enthalpy change of the reaction stayed the same.
Aniline can be produced from nitro-benzene by reduction. When nitro-benzene reacts with tin (Sn) + hydrochloride acid (HCl) then aniline is produced. The Sn + HCl forms free hydrogen ions which converts the nitro group of the benzene ring to amine group, which is aniline. In place of Sn + HCl. One can use palladium (Pd) hydrogen mixture in presence of ethanol (EtOH). There produces a side product in this reaction which is cyclohexyl amine. The reaction can be shown as.
Refer to the diagram shown below.
The second axis is at the centroid of the rod.
The length of the rod is L = 100 cm = 1 m
The first axis is located at 20 cm = 0.2 m from the centroid.
Let m = the mass of the rod.
The moment of inertia about the centroid (the 2nd axis) is

According to the parallel axis theorem, the moment of inertia about the first axis is

The ratio of the moment of inertia through the 2nd axis (centroid) to that through the 1st axis is

Answer: 0.676