Answer:
Volume of NaOH required = 3.61 L
Explanation:
H2SO3 is a diprotic acid i.e. it will have two dissociation constants given as follows:
--------(1)
where, Ka1 = 1.5 x 10–2 or pKa1 = 1.824
--------(2)
where, Ka2 = 1.0 x 10–7 or pKa2 = 7.000
The required pH = 6.247 which is beyond the first equivalence point but within the second equivalence point.
Step 1:
Based on equation(1), at the first eq point:
moles of H2SO3 = moles of NaOH
Step 2:
For the second equivalence point setup an ICE table:
Initial 1.98 ? 0
Change -x -x x
Equil 1.98-x ?-x x
Here, ?-x =0 i.e. amount of OH- = x
Based on the Henderson buffer equation:
![pH = pKa2 + log\frac{[SO3]^{2-} }{[HSO3]^{-} } \\6.247 = 7.00 + log\frac{x}{(1.98-x)} \\x=0.634 moles](https://tex.z-dn.net/?f=pH%20%3D%20pKa2%20%2B%20log%5Cfrac%7B%5BSO3%5D%5E%7B2-%7D%20%7D%7B%5BHSO3%5D%5E%7B-%7D%20%7D%20%5C%5C6.247%20%3D%207.00%20%2B%20log%5Cfrac%7Bx%7D%7B%281.98-x%29%7D%20%5C%5Cx%3D0.634%20moles)
Volume of NaOH required is:
Step 3:
Total volume of NaOH required = 3.22+0.389 =3.61 L
Deltas are formed by deposits of sediments, soil, sand, and gravel.
Solution :
It is given that :
The formula of the compound = 
And that 4.70 g of the sample contains 
mol of Br.
It means that :
1 mol of contains = 3 mol of Br
∴ 3 mol of 
contain in 1 mol of
mol of contains 
mol of
Thus the mol of = mol
The given mass is = 4.700 g
Therefore, the 
of 
= 298.4 g/mol
So of = of X + 3 x of Br
298.4 g/mol = of X + 3 x 79.90 g/mol
298.4 g/mol = of X + 239.7 g/mol
of X = 58.71 g/mol (since 1 amu = 1 g/mol)
Therefore the atomic mass of the unknown metal = 58.71 g/mol
So the unknown meta is Nickel.
From reliable sources in the web, it may be searched that the specific heat of copper is approximately equal to 0.385 J/gC. The amount of heat that is required to raise a certain amount by certain number of degrees is given in the equation,
H = mcpdT
where H is heat, m is mass, cp is specific heat, and dT is temperature difference. Substituting the known values,
186,000 J = (m)(0.385 J/gC)(285C)
m = 1695.15 g
