Answer:
6.73g
Explanation:
T½ = 5.2days
No = 80g
N = ?
T = 20.8days
We'll have to find the disintegration constant first so that we can plug it into the equation that will help us find the mass of the sample after 20.8 days
T½ = In2 / λ
T½ = half life
λ = disintegration constant
λ = In2 / T½
λ = 0.693 / 5.8
λ = 0.119
In(N / No) = -λt
N = final mass of the radioactive sample
No = initial mass of the sample
λ = disintegration constant
t = time for the radioactive decay
In(N/No) = -λt
N / No = e^-λt
N = No(e^-λt)
N = 80 × e^-(0.119 × 20.8)
N = 80 × e^-2.4752
N = 80 × 0.0841
N = 6.728g
The mass of the sample after 20.8 days is approximately 6.73g
Answer:
The correct statements are (II) and (III).
Explanation:
Any change in the equilibrium is studied on the basis of Le-Chatelier's principle.
This principle states that if there is any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.
For the given equation:
This is a type of exothermic reaction because heat is released in the reaction.
On increasing the temperature
If the temperature is increased, so according to the Le-Chatlier's principle , the equilibrium will shift in the direction where decrease in temperature occurs. As, this is an exothermic reaction, forward reaction will increase the temperature. Hence, the equilibrium will shift in the left direction.
And by moving to left side amount of ammonia will decrease accompanied by the change in the value of an equilibrium constant.
Answer:
127 mL is the volume for the 45.8 g of LiCl
Explanation:
Molarity of solution: 8.50 M
We know, from this data that 8.50 moles of solute (LiCl), are in 1L of solution
Let's find out the volume for the 45.8 g of LiCl, by a rule of three.
We convert the mass to moles, before: 45.8 g . 1mol / 42.39g = 1.08 moles
Therefore:
8.50 moles of LiCl are found in 1L of solution
Our 1.08 moles will be found in (1.08 mol . 1L) / 8.50 mol = 0.127 L
We can convert the volume from L to mL: 0.127L . 1000 mL/1L = 127mL
I believe Jose is correct because though the book isn't moving, gravity is still being applied (gravity counts as force)
Explanation:
Hoped this helped