Answer: 3
Explanation: This is a radioactive decay and all the radioactive process follows first order kinetics.
Equation for the reaction of decay of 
radioisotope follows:
By the stoichiometry of above reaction,
1 mole of 
is produced by 1 mole 
So, 0.17 moles of will be produced by = 
Amount of 
decomposed will be = 0.17 moles
Initial amount of 
will be = Amount decomposed + Amount left = (0.17 + 0.024)moles =0.194 moles
where,
a = amount of reactant left after n-half lives = 0.024
= Initial amount of the reactant = 0.194
n = number of half lives= ?
Putting values in above equation, we get:
Therefore, 3 half lives have passed.
Reduction refers to a chemical reaction in which electrons are gained by one of the atoms involved in the reaction and at the same time lowering of an oxidation state of that atom takes place.
In the given case, the reduction occurs at the cathode. In aqueous, V (vanadium) is present in +5 oxidation state that on reduction modifies to vanadium (aq) with +1 oxidation state.
The half reaction is:
V⁵⁺ (aq) + 4e⁻ → V¹⁺ (aq)
Take a look at the attached picture. This is not the reaction of polymerization of salicylic acid. It just shows the structure of salicylic acid and the structure when it's polymerized. The polymerization is done by connecting the salicylic acids where you produce one molecule of water.
Answer
a) A solution with a hydronium molarity of 0.00045 is acidic. True
Doing the calculus of pH
![pH= -Log [H^{+}] = -Log (0.00045)](https://tex.z-dn.net/?f=pH%3D%20-Log%20%5BH%5E%7B%2B%7D%5D%20%3D%20-Log%20%280.00045%29)
b) pH is a way to express the hydronium concentration over a wide range. True
pH means –Log[H+] and this value is used to express a wide range of hydronium concentration sometimes obtaining pH minor than zero.
c) Percent K and Fe are determined by doing ion exchange then a pH titration. False
Usually, Fe is determined by redox titration with potassium permanganate due to it’s more accurate. On the other hand, K is determined usually by volumetric process which includes precipitation like potassium picrate precipitate
d) About 0.2M HCl is the reagent used for the pH titrations. False.
In order to do pH titration, it is possible to use a wide range of HCl concentrations and other acids as reagent if the analyte is a basic compound. Otherwise, if the analyte is an acid compound you should use a basic compound as reagent.
e) A Lewis base is specie that can donate a proton to an acid. False
A Lewis base is an electron pair donor.
Answer:
4.16L
Explanation:
From the question given, we obtained the following data:
Molarity = 0.225 M
Number of mole of KI = 0.935mole
Volume =?
Molarity = mole / Volume
Volume = mole /Molarity
Volume = 0.935/0.225
Volume = 4.16L
Therefore, 4.16L of KI is needed.
