Answer:- 9.4 minutes.
Solution:- Radioactive decay obeys first order reaction kinetics and the equation used to solve this type of problems is:
where, k is decay constant and t is the time. is the initial amount of the radioactive substance and N is the remaining amount.
Since the value of decay constant is not given, so we need to calculate it first from given half life by using the formula:
where stands for half life.
Given half life is 3.0 minutes.
So,
Let's plug in the values in the first order reaction equation and solve it for t.
It could also be written as:
k = 9.4 min
So, the radioactive substance would take 9.4 minutes to decay from 40.0 grams to 4.5 grams.
Answer:
0
Explanation:
Since HI is a strong acid, the amoung of Hydrogen ions produced by it will be the same molar as the reactant. The negative log of the concentration will reveal that the pH is 0.
Answer:
The volume of solution in liters required to make a 0.250 M solution from 3.52 moles of solute is 14.08 liters of solution
Explanation:
The question relates to the definition of the concentration of a solution which is the number of moles per liter (1 liter = 1 dm³) of solution
Therefore we have;
The concentration of the intended solution = 0.250 M
Therefore, the number of moles per liter of the required resolution = 0.250 moles
Therefore, the concentration of the required solution = 0.250 moles/liter
The volume in liters of the required solution that will have 3.52 moles of the solute is given as follows;
The required volume of solution = The number of moles of the solute/(The concentration of the solution)
∴ The required volume of solution = 3.52 moles/(0.250 moles/liter) = 14.08 liters
The required volume of solution to make a 0.250 M solution from 3.52 moles of solute = 14.08 liters.
Therefore the number of liters required to make a 0.250 M solution from 3.52 moles of solute = 14.08 liters.