First, we have to write a balanced equation for the production of ammonia (NH₃) from hydrogen gas (H₂) and nitrogen gas (N₂):
N₂ + 3H₂ → 2NH₃
Now, the mole ratio of H₂ : NH₃ is 3 : 2 based on the coefficients of the balanced equation.
If the moles of H₂ = 15 moles
then the moles of NH₃ produced = (15 mol ÷ 3) × 2
= 10 mol
Thus, the number of moles of NH₃ produced when 15 mol of hydrogen gas is combined with excess nitrogen gas is 10 mol.
Answer: The concentration of 
will be 
after 416 seconds have passed.
Explanation:
Expression for rate law for first order kinetics is given by:
where,
k = rate constant = 
t = age of sample = ?
a = let initial amount of the reactant = 
a - x = amount left after decay process =
The concentration of will be after 416 seconds have passed.
Answer:
768g
Explanation:
We can use to formula 
. Here, N(A) is the final amount. N0 is the initial amount. t is the time elapsed, and 
is the half life. Plugging in, we get the answer above.
Net overall dissociation:
Na2CO3 ---> 2Na(-) + CO3(2-)
*The ion charge is in parenthesis
