Answer:
43.93 g/mol
Explanation:
The mass of the gas before reaction = 52.1487 g
The mass of the gas after reaction = 52.1098 g
Mass of gas generated = 0.0389 g
Moles of the gas = 
The formula for the calculation of moles is shown below:

Thus,


Molar mass of the gas = 43.93 g/mol
Answer:
q = 14049 J
Explanation:
q = m*c*(t2-t1)
q = 350 * 0.892 * (70-25) =
312.2 * 45 = 14049 J
I might be getting a little confused but I could be right.
Hope this helps!
Answer:
In first shell 2 electrons are present and 7 electrons are present in last shell
Explanation:
Number of Atoms in Gold for given mass can be calculated using following formula,
# of Moles = Number of Atoms / 6.022 × 10²³
Or,
Number of Atoms = Moles × 6.022 × 10²³ ------- (1)
Calculating Moles,
As,
Moles = Mass / M.mass
So,
Moles = 4.25 g / 196.96 g/mol
Moles = 0.0215
Putting value of mole in eq.1,
Number of Atoms = 0.0215 × 6.022 × 10²³
Number of Atoms = 1.299 × 10²²
Result:
4.25 g of Gold Nugget contains 1.299 × 10²² Atoms.