Answer:
11552.45 years
Explanation:
Given that:
Half life = 5730 years
Where, k is rate constant
So,
The rate constant, k = 0.00012 years⁻¹
Using integrated rate law for first order kinetics as:
Where,
is the concentration at time t
is the initial concentration
Given that:
The rate constant, k = 0.00012 years⁻¹
Initial concentration
= 160.0 counts/min
Final concentration
= 40.0 counts/min
Time = ?
Applying in the above equation, we get that:-

For the first part, use the question M=mol/vol (liters)
To do this, you have the given 1.6 M solution
divide the 360g by the molar mass of ethanol (44.07) to get moles
360/44.07=8.16 mol
so
1.6M = 8.16 mol/x vol
volume: 5.1 Liters
A solution (in this experiment solution of NaNO₃) freezes at a lower temperature than does the pure solvent (deionized water). The higher the
solute concentration (sodium nitrate), freezing point depression of the solution will be greater.
Equation describing the change in freezing point:
ΔT = Kf · b · i.
ΔT - temperature change from pure solvent to solution.
Kf - the molal freezing point depression constant.
b - molality (moles of solute per kilogram of solvent).
i - Van’t Hoff Factor.
First measure freezing point of pure solvent (deionized water). Than make solutions of NaNO₃ with different molality and measure separately their freezing points. Use equation to calculate Kf.