Answer:
138.96kJ is the maximum electrical work
Explanation:
The maximum electrical work that can be obtained from a cell is obtained from the equation:
W = -nFE
<em>Where W is work in Joules,</em>
<em>n are moles of electrons = 2mol e- because half-reaction of Zn is:</em>
Zn(s) → Zn²⁺(aq) + 2e⁻
F is faraday constant = 96500Coulombs/mol
E is cell potential = 0.72V
Replacing:
W = -2mol*96500Coulombs/mol*0.72V
W = - 138960J =
<h3>138.96kJ is the maximum electrical work</h3>
<em />
Answer: 42.14 g
Explanation: calcium nitrate - 
, the molar mass of calcium nitrate = 164 g
<h3> formula used =
= no of moles </h3>
mass required =
=
g
Gasoline contains C and H atoms. During combustion, the carbon (C) from the fuel combines with oxygen (O2) from the air to produce carbon dioxide (CO2).
2 C8H18 + 25 O2 → 16 CO2 + 18 H2O.
Combustion reactions release large amounts of heat. They have negative enthalpy. A negative enthalpy represents an exothermic reaction, releasing heat. This reaction is spontaneous and exothermic, since we can obtain energy from the reaction; the ΔG (free energy) is negative (So 1 is true).
ΔG < 0, so the free energy of the system decreases with the reaction. Remember that when there is a negative ΔG the reaction goes from higher free energy to lower free energy, like in this case.
Answer:
5 mol.
Explanation:
Equation of the reaction
2SO2 + 2H2O + O2 --> 2H2SO4
By stoichiometry, 2 moles of SO2 reacted with 2 moles of water and 1 mole of O2 to give 2 mole of sulphuric acid.
Number of moles:
5.0 mol SO2
4.0 mol O2
20.0 mol H2O
Calculating the limiting reagent,
5 mol of SO2 * 1 mol of O2/2 mol of SO2
= 2.5 mol of O2(4 mol of O2 is present)
5 mol of SO2 * 2 mol of H2O/2 mol of SO2
= 5 mol of H2O(20 mol of H2O)
SO2 is the limiting reagent.
Therefore, number of moles of H2SO4 = 5 mol of SO2 * 2 mol of H2SO4/2 mol of SO2
= 5 mol of H2SO4.
