Protons: 12
Neutrons: 13
<span>Electrons: 12</span>
Answer:
M = 0.23 M
Explanation:
Given data:
Molarity of solution = ?
Mass of NH₄Br = 4.50 g
Volume of solution = 213 mL (213 mL× 1L /1000 mL = 0.213 L)
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Number of moles of NH₄Br:
Number of moles = mass/molar mass
Number of moles = 4.50 g / 97.94 g/mol
Number of moles = 0.05 mol
Molarity:
M = 0.05 mol/ 0.213 L
M = 0.23 M
Answer: The molar mass of the gas is 9.878 g/mol.
Explanation:
According to Graham's law, the rate of diffusion is inversely proportional to square root of molar mass of gas.
where,
M = molar mass of gas
As given gas diffuses 1/7 times faster than hydrogen gas. So, its molar mass is calculated as follows.
where,
= molar mass of hydrogen gas
= molar mass of another given gas
= rate of diffusion of hydrogen
= rate of diffusion of another given gas = 
Substitute the values into above formula as follows.
Thus, we can conclude that the molar mass of the gas is 9.878 g/mol.
