Answer:
-179.06 kJ
Explanation:
Let's consider the following balanced reaction.
HCl(g) + NaOH(s) ⟶ NaCl(s) + H₂O(l)
We can calculate the standard enthalpy change for the reaction (ΔH°r) using the following expression.
ΔH°r = 1 mol × ΔH°f(NaCl(s)) + 1 mol × ΔH°f(H₂O(l)) - 1 mol × ΔH°f(HCl(g)) - 1 mol × ΔH°f(NaOH(s))
ΔH°r = 1 mol × (-411.15 kJ/mol) + 1 mol × (-285.83 kJ/mol) - 1 mol × (-92.31 kJ/mol) - 1 mol × (-425.61 kJ/mol)
ΔH°r = -179.06 kJ
The change in internal energy of the combustion of biphenyl in Kj is calculated as follows
=heat capacity of bomb calorimeter x delta T where delta T is change in temperature
delta T = 29.4 -25.8= 3.6 c
= 5.86 kj/c x 3.6 c = 21.096 kj
There are 13 atoms in the product
<h3>Further explanation</h3>
Given
Reaction
H2SO4 + 2KOH --> K2SO4 + 2H2O
Required
The number of atoms
Solution
In a chemical equation, there are reactants on the left and products on the right
Reactants : H2SO4 + 2KOH
Products : K2SO4 + 2H2O
The number of atoms is determined by their reaction coefficient and the subscript of the atoms in the compound
K2SO4 (coefficient = 1) :
K = 2 atoms
S = 1 atom
O = 4 atoms
Total atoms = 7 atoms
2H2O(coefficient = 2) :
H = 2 x 2 = 4 atoms
O = 2 x 1 = 2 atoms
Total atoms = 6 atoms
Total = 13 atoms
Answer: -40
Explanation: Percent error is calculated by subtracting the value you actually recieved from the literature value (175 in your case) SO your answer should be 135-175=-40.
