2AgNO3 + Ni2+ = Ni(NO3)2 + 2Ag<span>+</span>
From the reaction,
it can be seen that AgNO3 and Ni2+ has following amount of substance
relationshep:
n(AgNO3):n(Ni)=2:1
From the relationshep we can determinate requred moles of Ni2+:
n(AgNO3)=m/M= 15.5/169.87=0.09 moles
So, n (Ni)=n(AgNO3)/2=0.045 moles
Finaly needed mass of Ni2+ is:
m(Ni2+)=nxM=0,045x58.7=2.64g
C; The Valence electrons spend more time around the atom of F
By stirring and increasing temperature, there is an increase in dissolving capacity of the solid solute.
<u>Explanation:</u>
If a solute is added to the solution, it doesn't get dissolve easily then we have to increase the temperature, which in turn increases the movement of the solvent (may be water) and the solute particles, thus increases the dissolving power of the solid solute. One more way is by constant stirring, that is by making more contact among the solvent as well as the solute particles there by increasing the solubility of solid solute.
Explanation:
A reaction quotient is defined as the ratio of concentration of products over reactants raised to the power of their stoichiometric coefficients.
A reaction quotient is denoted by the symbol Q.
For example, 
The reaction quotient for this reaction is as follows.
Q = ![\frac{[Fe^{2+}]^{2}[Zn^{2+}]}{[Fe^{3+}]^{2}}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BFe%5E%7B2%2B%7D%5D%5E%7B2%7D%5BZn%5E%7B2%2B%7D%5D%7D%7B%5BFe%5E%7B3%2B%7D%5D%5E%7B2%7D%7D)
[Zn] will be equal to 1 as it is present in solid state. Therefore, we don't need to write it in the reaction quotient expression.