Answer:
The pH of the buffer solution = 8.05
Explanation:
Using the Henderson - Hasselbalch equation;
pH = pKa₂ + log ( [HPO₄²-]/[H₂PO4⁻]
where pKa₂ = -log (Ka₂) = -log ( 6.1 * 10⁻⁸) = 7.21
Concentration of OH⁻ added = 0.069 M (i.e. 0.069 mol/L)
[H₂PO4⁻] after addition of OH⁻ = 0.165 - 0.069 = 0.096 M
[HPO₄²-] after addition of OH⁻ = 0.594 + 0.069 = 0.663 M
Therefore,
pH = 7.21 + log (0.663 / 0.096)
pH = 7.21 + 0.84
pH = 8.05
The atomic mass is determined by the number of protons and neutrons in a atoms for example oxygen has eight protons and neutrons which gives oxygen and atomic mass of 16
1/6 x 1/6 x 1/6= solve the rest
Answer:
1000N is needed to be applied.
Explanation:
Machines make doing work easier. They allow us use small effort to carry out work on huge amount of load.
The mechanical advantage of a machine;
(M.A) =load/effort
M.A = 0.6
Load =600N
effort =?
0.6 = 600/effort
effort = 600/0.6
effort = 1000N
Answer : The final temperature of the solution in the calorimeter is, 
Explanation :
First we have to calculate the heat produced.
where,
= enthalpy change = -44.5 kJ/mol
q = heat released = ?
m = mass of 
= 1.52 g
Molar mass of = 40 g/mol
Now put all the given values in the above formula, we get:
Now we have to calculate the final temperature of solution in the calorimeter.
where,
q = heat produced = 1.691 kJ = 1691 J
m = mass of solution = 1.52 + 35.5 = 37.02 g
c = specific heat capacity of water = 
= initial temperature = 
= final temperature = ?
Now put all the given values in the above formula, we get:
Thus, the final temperature of the solution in the calorimeter is,
