The acidity or alkalinity of an unknown aqueous solution is indicated by its

Answer:

C.

Explanation:

Metals tends to lose electrons and form positive ions, known as cations. Whereas, non-metals tend to gain electrons and form negative ions known as anions.

Answer:

C. Metal, nonmetal

Explanation:

Fill in the blanks

The metal elements tend to lose electrons and form positive ions, while the non-metal elements tend to gain electrons and form negative ions.

Answer: Therefore, the molar mass of the unknown substance is 68.4 g/mol.

Explanation: We can use the freezing point depression equation to solve for the molar mass of the unknown substance:

ΔT = Kf × m

where ΔT is the change in freezing point, Kf is the freezing point depression constant of the solvent (naphthalene), and m is the molality of the solution.

First, we need to calculate the molality of the solution:

molality = moles of solute / mass of solvent (in kg)

We don't know the number of moles of the unknown substance, but we can assume that the naphthalene does not contribute significantly to the total mass of the solution (since its mass is much smaller than the mass of the unknown substance). Therefore, we can use the entire mass of the solution (1000g + 12.3g = 1012.3g) as the mass of solvent.

mass of solute = 1000g

mass of solvent = 12.3g

mass of solution = 1012.3g

molality = (1000g / molar mass) / (12.3g / 1000g) = 81.3 / molar mass

Next, we need to calculate the change in freezing point:

ΔT = 1.2∘C

Finally, we can use the freezing point depression constant of naphthalene to solve for the molar mass of the unknown substance:

Kf for naphthalene = 6.8∘C/m

ΔT = Kf × m

1.2 = 6.8 × (81.3 / molar mass)

molar mass = 68.4 g/mol

Therefore, the molar mass of the unknown substance is 68.4 g/mol.