10, it has gained and electron which increases the charge, as the -1 indicates
Answer:
Vapour pressure of solution is 78.151 torr
Explanation:
Molar mass of biphenyl = 154.21 g
Molar mass of benzene = 78.11 g
19.2 g biphenyl = (19.2/154.21) moles of biphenyl = 0.125 moles of biphenyl
33.7 g of benzene = (33.7/78.11) moles of benzene = 0.431 moles of benzene
Total number of moles = (0.125+0.431) moles = 0.556 moles
Mole fraction of benzene in solution = (0.431/0.556) = 0.775
According to Roults law, vapour pressure of solution made from non-volatile solute = 
Here solute is biphenyl and solvent is benzene
So, vapour pressure of solution = 
= 78.151 torr
Assuming you are talking about the atomic mass of magnesium chloride
M = n/V
M = 1/3.77
M = .265
Answer: -
¹⁰B
Explanation: -
For ⁹Be,
The atomic number is 4.
The Mass number is 9.
The number of neutrons = mass number - atomic number
= 9 - 4 = 5
For ⁹B,
The atomic number is 5.
The Mass number is 9.
The number of neutrons = mass number - atomic number
= 9-5 = 4
For ¹⁰B,
The atomic number is 5.
The Mass number is 10.
The number of neutrons = mass number - atomic number
= 10-5 = 5
For ¹⁰Be,
TThe atomic number is 4.
The Mass number is 10.
The number of neutrons = mass number - atomic number
= 10-4 = 6
For ¹²C,
The atomic number is 6.
The Mass number is 12.
The number of neutrons = mass number - atomic number
= 12-6 = 6
