The mass decay rate is of the form

where
m₀ = 3000 g,the initial mass
k = the decay constant
t = time, years.
Because the half-life is 30 years, therefore

After 60 years, the mass remaining is

Answer: 750 g
Answer:
Explanation:
The reaction is given as:

The reaction quotient is:
![Q_C = \dfrac{[NH_3]^2}{[N_2][H_2]^3}](https://tex.z-dn.net/?f=Q_C%20%3D%20%5Cdfrac%7B%5BNH_3%5D%5E2%7D%7B%5BN_2%5D%5BH_2%5D%5E3%7D)
From the given information:
TO find each entity in the reaction quotient, we have:
![[NH_3] = \dfrac{6.42 \times 10^{-4}}{3.5}\\ \\ NH_3 = 1.834 \times 10^{-4}](https://tex.z-dn.net/?f=%5BNH_3%5D%20%3D%20%5Cdfrac%7B6.42%20%5Ctimes%2010%5E%7B-4%7D%7D%7B3.5%7D%5C%5C%20%5C%5C%20NH_3%20%3D%201.834%20%5Ctimes%2010%5E%7B-4%7D)
![[N_2] = \dfrac{0.024 }{3.5}](https://tex.z-dn.net/?f=%5BN_2%5D%20%3D%20%5Cdfrac%7B0.024%20%7D%7B3.5%7D)
![[N_2] = 0.006857](https://tex.z-dn.net/?f=%5BN_2%5D%20%3D%200.006857)
![[H_2] =\dfrac{3.21 \times 10^{-2}}{3.5}](https://tex.z-dn.net/?f=%5BH_2%5D%20%3D%5Cdfrac%7B3.21%20%5Ctimes%2010%5E%7B-2%7D%7D%7B3.5%7D)
![[H_2] = 9.17 \times 10^{-3}](https://tex.z-dn.net/?f=%5BH_2%5D%20%3D%209.17%20%5Ctimes%2010%5E%7B-3%7D)
∴

However; given that:

By relating
, we will realize that 
The reaction is said that it is not at equilibrium and for it to be at equilibrium, then the reaction needs to proceed in the forward direction.
The number is is surely 1
The answer is 0.600 M; but I don't know how to get to that answer.