Answer: The enthalpy of the reaction is -109 kJ
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.
(1)
(2)
The final reaction is:
Subtracting (2) from (1):
Thus the enthalpy of the reaction is -109 kJ
The mathematical expression for heat capacity at constant pressure is given as:
(1)
where, Q = heat capacity
= molar heat capacity at constant pressure
= change in temperature
n = number of moles
Therefore, = 
= 
Number of moles =
= 
= 0.186 mole
Put the values in formula (1)
(conversion of degree Celsius into kelvin)
= 
= 6.32 J /mol K
Hence, molar heat capacity of benzene at constant pressure = 
Answer:
72.67g of B
Explanation:
The reaction of B₂O₃ to produce boron (B), is:
B₂O₃ → 3/2O₂ + 2B
<em>That means B₂O₃ produce 2 moles of boron</em>
Molar mass of B₂O₃ is 69.62g/mol. 234g of B₂O₃ contains:
234g B₂O₃ ₓ (1mol / 69.62g) = 3.361 moles of B₂O₃.
As 1 mole of B₂O₃ produce 2 moles of B, Moles of B that can be produced from B₂O₃ is:
3.361mol B₂O₃ ₓ 2 = <em>6.722 moles of B</em>.
As molar mass of B is 10.811g/mol. Thus mass of B that can be produced is:
6.722mol B ₓ (10.811g / mol) = <em>72.67g of B</em>
The intended sense is that of a reaction that depends on absorbing heat if it is to proceed. The opposite of an endothermic process is an exothermic process, one that releases "gives out" energy in the form of heat
Answer:An ion with 5 protons, 6 neutrons and a charge of 3+ has an atomic number of 5
Explanation:
