Answer:
Ag+
Explanation:
If you imagine as if the problem were double replacement, you would pair the Cl with one of the following ions provided in the choices. As seen on Table F, Ag+ paired with Cl- produces an insoluble compound, hence the precipitate. All the other ions shown in the multiple choice section, when paired with Cl- will produce a soluble compound, as a result NOT a precipitate.
Answer : The new pressure if the volume changes to 560.0 mL is, 280 mmHg
Explanation :
According to the Boyle's, law, the pressure of the gas is inversely proportional to the volume of gas at constant temperature and moles of gas.

or,

where,
= initial pressure = 560.00 mmHg
= final pressure = ?
= initial volume = 280 mL
= final volume = 560.0 mL
Now put all the given values in the above formula, we get:


Therefore, the new pressure if the volume changes to 560.0 mL is, 280 mmHg
Ion-dipole forces
H2O has hydrogen bonding, which is a form of dipole-dipole forces, and NO3- is an ion, so the intermolecular attraction is ion-dipole.