The steps to be followed while cleaning volumetric glassware are:
1. Remnants from the previous measurements are wiped off with the help of paper towel.
2. The glassware is then soaked overnight in warm soap solution.
3. Then before rinsing with tap water, the glassware are scrubbed with an appropriate brush.
4. After scrubbing, the glassware is rinsed thoroughly with tap water in order to make sure there are no traces of soap solution.
5. The glassware is then rinsed with de-ionized water and finally with the solution that would be used for the volumetric measurement.
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:-
Answer:
10.945 x 10^-4
Explanation:
Balanced equation:
Mn(OH)2 + 2 HCl --> MnCl2 + H2O
it takes 2 moles HCL for each mole Mn(OH)2
Next find the molarity of the Mn(OH)2 solution
= (1 mole Mn(OH)2 / 2 mole HCl) X (0.0020 mole HCl / 1000ml) X (4.86 ml)
= 4.86 x 10^-3 mole
this is now dissolved in (70 + 4.86) = 74.86 ml or 0.07486 L
thus [Mn(OH)2] = 4.86 x 10^-3 mole / 0.07486 L = 0.064921 M
Ksp = [Mn2+][OH-]^2 = 4x^3 = 4(0.064921)^3 = 10.945 x 10^-4