Answer:
9.28
Explanation:
pOH refers to a measure of hydroxide ions concentration. pOH tells about the alkalinity of a solution. If pOH is less than 7 then aqueous solutions are alkaline, acidic if pOH is greater than 7 and neutral if pOH is equal to 7.
Concentration of the hydroxide ions = 1.9 x 10-5 M
pH = 
pOH = 14 - pH
=14 - 4.72 = 9.28
Ur answer is going to be francium
Adding (S2O3)2- would affect the reaction mechanism that involves this ion. From the reaction mechanism given above, the equilibrium of step 2 would be affected. Adding the stock solution of (S2O3)2- would shift the equilibrium to the right thus making more products of the said mechanism. Also, the reaction rate of this step would occur faster than the original rate. This is based on Le Chatelier's Prinicple which states that a corresponding change would happen to the equilibrium of a reaction when pressure, concentration of the substances or temperature is changed. So, that after the addition, a color change would appear immediately because I3- would be removed slowly from solution, and would therefore be able to react with starch.
Answer:GASEOUS, LOWERING ,EMITTED AS HEAT, DOWN,DO NOT RELEASE,DECREASES,NEGATIVE.
Explanation: Filling the blanks gives
Lattice energy is associated with forming a crystalline lattice of alternating cations and anions from the _GASEOUS___________ ions.
Because the cations are positively charged and the anions are negatively charged, there is a LOWERING of potential- as described by Coulomb's law-when the ions come together to form a lattice energy.That energy is EMITTED AS HEAT when the lattice forms.
As the ionic radii increases as you move DOWN a group, ions cannot get as close to each other and therefore DO NOT RELEASE as much energy when the lattice forms. Thus the lattice energy DECREASES (becomes less) NEGATIVE as the radius increases.
The above gives the definition of Lattice Energy and how it relates to atomic and ion charge.
