Answer:
2059.645g Cl
Explanation:
A mole of any element contains 6.022e23 molecules, so we will divide the given amount of molecules by 6.022e23.
3.5e25 / 6.022e23 = 5.81e1
5.81e1 = 58.1 mol Cl
Now that we have found the amount of moles of Chlorine, we will multiply the number of moles by the molar mass of Chlorine, which is 35.45g/mol.
35.45(58.1) = 2059.645g Cl
Answer:
Option (B) is correct
Explanation:
Oxidation: 
Reduction: 
---------------------------------------------------------------------------
Overall: 
Nernst equation for this cell reaction at 
:
![E_{cell}=(E_{Sn^{2+}\mid Sn}^{0}-E_{Zn^{2+}\mid Zn}^{0})-\frac{0.059}{n}log\frac{[Zn^{2+}]}{[Sn^{2+}]}](https://tex.z-dn.net/?f=E_%7Bcell%7D%3D%28E_%7BSn%5E%7B2%2B%7D%5Cmid%20Sn%7D%5E%7B0%7D-E_%7BZn%5E%7B2%2B%7D%5Cmid%20Zn%7D%5E%7B0%7D%29-%5Cfrac%7B0.059%7D%7Bn%7Dlog%5Cfrac%7B%5BZn%5E%7B2%2B%7D%5D%7D%7B%5BSn%5E%7B2%2B%7D%5D%7D)
Where, n is number of electron exchanged and species inside third bracket represents concentrations in molarity.
Here, n = 2, 
and ![[Zn^{2+}]=2.5\times 10^{-3}M](https://tex.z-dn.net/?f=%5BZn%5E%7B2%2B%7D%5D%3D2.5%5Ctimes%2010%5E%7B-3%7DM)
So, plug in all the given values into above equation:
![0.660V=(-0.136V+0.76V)-\frac{0.059}{2}log\frac{2.5\times 10^{-3}M}{[Sn^{2+}]}](https://tex.z-dn.net/?f=0.660V%3D%28-0.136V%2B0.76V%29-%5Cfrac%7B0.059%7D%7B2%7Dlog%5Cfrac%7B2.5%5Ctimes%2010%5E%7B-3%7DM%7D%7B%5BSn%5E%7B2%2B%7D%5D%7D)
So, ![[Sn^{2+}]=4.2\times 10^{-2}M](https://tex.z-dn.net/?f=%5BSn%5E%7B2%2B%7D%5D%3D4.2%5Ctimes%2010%5E%7B-2%7DM)
As the value "0.059" varies from literature to literature and 
is most closest to 
therefore option (B) is correct.
Answer:
0.375 L
Explanation:
We know that at neutralization, the number of mol of acid must equal the number of equivalents of base.
This is a reaction 1:1 acid to base:
HClO₄ + NaOH ⇒ NaClO₄ + H₂O
We re given the moles of the base indirectly since we know the volume and molarity. From there we can calculate the volume of HClO₄.
Moles NaOH = 0.115 L x 0.244 M = 0.115 L x 0.244 mol/L =0.028 mol
Thus we require 0.028 mol of HClO₄ in the pechloric acid solution:
Molarity = # moles / V ⇒ V = # moles / M
V = 0.028 mol / 0.0748 mol/L = 0.375 L
Note that this problem can be solved in just one step since
M(HClO₄) x V(HClO₄) = M(NaOH) x V(NaOH) ⇒
V(HClO₄) = M(NaOH) x V(NaOH) / M(HClO₄)
Answer: HA + H2O ⇌ H3O+ + H- (option #4)
Explanation: Since the acid is weak you have to use a ⇌ (equilibrium) sign. Equilibrium is denoted in a chemical equation by the ⇌ symbol. Also, when any acid dissolves into water, it produces hydronium (H3O+ or H+). Therefore, the fourth chemical reaction is your answer.
