Maybe because the difference in weight
Percent composition is mass of element over mass of compound times 100. 6.41 + 9.60 = 16.01 g of compound, so % composition of sulfur is 6.41/16.01 x100 or 40.0%. % oxygen is 9.60/16.01 x 100 or 60.0%.
The chemical balanced equation for the given question is this:
2AL[NO3]3 + 3CaO = AL2O3 + 3Ca[NO3]2.
So, one of the product formed is AI2O3. The other product is Ca[NO3]2.
The reaction is a double replacement reaction.
Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar.
A positive cahnge of enthalpy, ΔH rxn = + 55 kJ/mol, for the forward reaction means that the reaction is endothermic, i.e. the reactants absorb energy and the products are higher in energy.
Activation energy is the difference in the energy level of the reactants and the peak in the potential energy diagram (the energy of the transition state).
For an endothermic reaction, the products will be closer in energy to the transition state than what the reactans will be; so, the activation energy of the reversed reaction is lower than the activation energy of the forward reaction.
Activation energy of reverse and forward reactions is related by:
Activation energy of reverse rxn = Activation energy of forward rxn - ΔH rxn
=> Activiation energy of reverse rxn = 102 kJ/mol - 55 kJ/mol = 47 kJ/mol
Answer: 47 kJ/mol