Science Questions

[joe001]

Hello,

Would appreciate if anyone can help with these two questions.

1. Compound T has a melting point of 78 °C and a boiling point of 134 °C. T is soluble in water and its solution does not conduct electricity. T has covalent bonding and has a simple molecular structure.
Which property of T is not usually associated with its bonding and structure?
A the melting point
B the boiling point
C the solubility in water
D the lack of conductivity of the solution

I don’t understand why C. is the answer, when entropy and polarity of a substance affect its solubility in water, and both of these are related to the structure of the molecule.


2.

I just would like to verify if when S2 is closed, what happens to A3. So it seems the total resistance is decreased when S2 is closed. That means current in A2 will increase, but current in A3 will be the same right?

3.

Could someone explain the reasoning behind answering this question? The answer is C.

Thank you.

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[Happy_Puppy5000]

This is months late and $50 short, but nevertheless.

The melting and boiling points are both affected by the polarity and size. Solubility tends to depend on the polarity of the molecule. Like dissolve like. So polar substances would be water soluble. However, compound T is not charged or polar--does not conduct electricity. (Choice C.)

The fact that compond T has a simple covalent structure, the intermolecular forces between the molecules are weak.

Comound T does not have mobile electrons, so as stated, it does not conduct electrity. That is, there are no ions to carry the charge in the structure. (Eliminating choice D.)


Both the melting and boiling point depends on the bonding structure [polarity and size] of the compound. Therefore, both the melting and boiling points are affected by bonding structure. Take water (H20) for example. Even though the molecule is tehradral structure with hydrogen at each end the molecule has a bend geometry and is still polar and capable of hydrogen bonding. On the other hand, carbon dioxide (CO2) is linear. Hence, both melting and boiling points are affected by structure. This eliminate bot choices A and B.


This respond is super late and very rambling. However, I hope it helps someone else. Good luck to all and happy Thanks Giving.