I would say A because it’s the only one that doesn’t conduct electricity. Ionic compounds conduct electricity, and covalent compounds do not.
Answer:
1 and 4
Explanation:
in both pictures the temperature is cooling down
The ch4 molecule exhibits hydrogen bonding.
This statement is false. A CH4 molecule do not have a hydrogen bonding instead it has dipole dipole attraction.
Hydrogen bonding occurs when a hydrogen atom is covalently bonded to an N, O, or F atom.
This would be a true statement. A hydrogen bond is present when an atom of hydrogen shares electrons with O, N or F atom.
A hydrogen bond is equivalent to a covalent bond.
This is a false statement. A hydrogen bond is an intermolecular force of attraction while covalent bond is a intramolecular force. So, they would mean different things.
a hydrogen bond is possible with only certain hydrogen-containing compounds.
This would be true. Without the presence of an hydrogen atom definitely there would be no hydrogen bond.
a hydrogen atom acquires a partial positive charge when it is covalently bonded to an f atom.
This would be true since a HF is a polar molecule.
To find the ratio of the the combination for the ion, write the charge of the cation as the subscript for the anion, and the charge of the anion as the subscript of the cation. This will make the charges effectively cancel and you will be left with a neutral ionic compound. Remember, that an ionic compound is made up of a metal and a nonmetal.
For Ca2+ and Cl-, you will get the neutral compound to be CaCl₂.
Total vapor pressure can be calculated using partial vapor pressures and mole fraction as follows:
Here, 
is mole fraction of A, 
is mole fraction of B, 
is partial pressure of A and 
is partial pressure of B.
The mole fraction of A and B are related to each other as follows:
In this problem, A is hexane and B is octane, mole fraction of hexane is given 0.580 thus, mole fraction of octane can be calculated as follows:
Partial pressure of hexane and octane is given 183 mmHg and 59.2 mmHg respectively.
Now, vapor pressure can be calculated as follows:
Putting the values,
Therefore, total vapor pressure over the solution of hexane and octane is 131 mmHg.
