Okay cool! thats not enough detail though
Answer:
2 moles of Sn are produced when 4 moles of H2(g) are consumed completely
Explanation:
to determine the number of moles of sn (l) produced when 4.0 moles of H2 (g) is consumed completely.
First, find the number of moles of H2 consumed by taking this as limiting reagent.

Then find the moles of Sn (l) taking into account the stoichiometric relationship between H2(g) and Sn(l). 2:1
(s) + 2
(g) ⇒ Sn(l) + 2
(g)

∴2 moles of Sn are produced when 4 moles of H2(g) are consumed completely.
Explanation:
Let us assume that the given data is as follows.
mass of barium acetate = 2.19 g
volume = 150 ml = 0.150 L (as 1 L = 1000 ml)
concentration of the aqueous solution = 0.10 M
Therefore, the reaction equation will be as follows.

Hence, moles of
=
.......... (1)
As, No. of moles =
Hence, moles of
will be calculated as follows.
No. of moles =
=
(molar mass of
is 255.415 g/mol)
= 
Moles of
= 
= 0.01715 mol
Hence, final molarity will be as follows.
Molarity = 
= 
= 0.114 M
Thus, we can conclude that final molarity of barium cation in the solution is 0.114 M.
Answer:
The most important resonance structure is 4 (attached picture). Its bon order is
or
.
Explanation:
A picture with 4 forms of the perchlorate structure is attached. The first structure has simple bonds. The second structure contains a double bond, the third structure has two double bonds and the fourth structure has three double bonds.
Formal charge = group number of the periodic table - number of bonds (number of bonding electrons / 2) - number of non-shared electrons (lone pairs)
The formal charges in the first structure is +3 in chlorine and -1 in oxygen.
The formal charges in the second structure is +2 in chlorine, -1 in oxygen and 0 in the double bond oxygen.
The formal charges in the third structure is +1 in chlorine, -1 in the single bond oxygens and 0 in the double bond oxygens.
The formal charges in the fourth structure is 0 in chlorine, -1 in the single bond oxygen and 0 in the double bond oxygens.
The most important resonance structure is given by:
- Most atoms have 0 formal charge.
- Lowest magnitude of formal charges.
- If there is a negative formal charge, it's on the most electronegative atom.
Hence, the fourth structure is the mosr important.
The bond order of the structure is:
Total number of bonds: 7
Total number of bond groups: 4
Bond order= 