Answer : The enthalpy of the reaction is, -2552 kJ/mole
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The given enthalpy of reaction is,

The intermediate balanced chemical reactions are:
(1)

(2)

(3)

(4)

Now we have to revere the reactions 1 and multiple by 2, revere the reactions 3, 4 and multiple by 2 and multiply the reaction 2 by 2 and then adding all the equations, we get :
(when we are reversing the reaction then the sign of the enthalpy change will be change.)
The expression for enthalpy of the reaction will be,



Therefore, the enthalpy of the reaction is, -2552 kJ/mole
2H2O+O2--->2H2O2
8.5 gm H2O2=0.25 mole
hence H2O is also 0.25 mole i.e.4.5 gm
O2is 0.125 mole i.e.4 gm
Answer:
0.22 mol HClO, 0.11mol HBr.
0.25mol NH₄Cl, 0.12 mol HCl
Explanation:
A buffer is defined as a mixture in solution between weak acid and its conjugate base or vice versa.
Potassium hypochlorite (KClO) could be seen as conjugate base of HClO (Weak acid). That means the addition of <em>0.22 mol HClO </em>will convert the solution in a buffer. HBr reacts with KClO producing HClO, thus, <em>0.11mol HBr</em> will, also, convert the solution in a buffer. 0.23 mol HBr will react completely with KClO and in the solution you will have only HClO, no a buffering system.
Ammonia (NH₃) is a weak base and its conjugate base is NH₄⁺. That means the addition of <em>0.25mol NH₄Cl</em> will convert the solution in a buffer. Also, NH₃ reacts with HCl producing NH₄⁺. Thus, addition of<em> 0.12 mol HCl</em> will produce NH₄⁺. 0.25mol HCl consume all NH₃.
To solve for the absolute temperature, we assume ideal gas
behaviour so that we use the equation:
PV = nRT
or T = PV / nR
So calculating:
T = [6.6 atm * 0.40 L] / [(2.4g / 28g/mol) * 0.08205746 L
atm / mol K]
<span>T = 375.35 K</span>
A single sodium ion will combine due to its charge on it
Na^+
The single sodium ion has total one positive charge on it. so it requires only one electron or can bond to one negative charge
in the given polyatomic anions
a) CO3^-2 : it has two negative charge. So it will react with two sodium ions
it will forms Na2CO3
b) PO4^-3 :it has three negative charge. So it will react with three sodium ions
it will forms Na3PO4
c) SO4^-2 : it has two negative charge. So it will react with two sodium ions
it will forms Na2SO4
d) NO3^-1: it has one negative charge. So it will react with one sodium ion
it will forms NaNO3
Hence the correct answer is
Nitrate ion will react with single sodium ion as
Na+ + NO3- ---> NaNO3