Answer:
0.6749 M is the concentration of B after 50 minutes.
Explanation:
A → B
Half life of the reaction =
Rate constant of the reaction = k
For first order reaction, half life and half life are related by:
Initial concentration of A =
Final concentration of A after 50 minutes =
t = 50 minute
[A] = 0.2251 M
The concentration of A after 50 minutes = 0.2251 M
The concentration of B after 50 minutes = 0.900 M - 0.2251 M = 0.6749 M
0.6749 M is the concentration of B after 50 minutes.
The question is incomplete, complete question is :
Determine the pH of an HF solution of each of the following concentrations. In which cases can you not make the simplifying assumption that x is small? ( for HF is
.)
[HF] = 0.280 M
Express your answer to two decimal places.
Answer:
The pH of an 0.280 M HF solution is 1.87.
Explanation:3
Initial concentration if HF = c = 0.280 M
Dissociation constant of the HF =
Initially
c 0 0
At equilibrium :
(c-x) x x
The expression of disassociation constant is given as:
Solving for x, we get:
x = 0.01346 M
So, the concentration of hydrogen ion at equilibrium is :
The pH of the solution is ;
The pH of an 0.280 M HF solution is 1.87.