Answer:
B. Intermolecular forces are hard to overcome
Explanation:
A high boiling point indicates greater inter molecular forces between the molecules of the substance. Inter molecular forces is the force of attraction between the molecules of the substance, which has to be overcome or broken before the substance boils. Example, when water boils, the water molecule (H₂O) will be broken into hydrogen molecule and oxygen molecule.
Therefore, a high boiling point temperature indicates that intermolecular forces of the substance are hard to overcome.
B. Intermolecular forces are hard to overcome
Answer:
1.36 × 10³ mL of water.
Explanation:
We can utilize the dilution equation. Recall that:

Where <em>M</em> represents molarity and <em>V</em> represents volume.
Let the initial concentration and unknown volume be <em>M</em>₁ and <em>V</em>₁, respectively. Let the final concentration and required volume be <em>M</em>₂ and <em>V</em>₂, respectively. Solve for <em>V</em>₁:

Therefore, we can begin with 0.640 L of the 2.50 M solution and add enough distilled water to dilute the solution to 2.00 L. The required amount of water is thus:

Convert this value to mL:

Therefore, about 1.36 × 10³ mL of water need to be added to the 2.50 M solution.
Answer:
a )Li
b)O
c)F
Explanation:
a) Li-1s^2 2s^1
F-1s^2 2s^2 2p^5
it is easy to pull out e- from 2p orbit than 2s because 2s orbit is close to nucleus.Therefore Li have high ionisation enthalpy
b)oxygen ion is larger than Na because o have fewer proton
c)F because it requires only 1e to achieve stable noble gas configuration.Therefore to achieve stable nobke gas electonic configuration it accept 1e.