Helium has an atomic number 2 and an atomic weight of 4 grams per mole. It is one of the noble gas (which means that it is stable) and also a nonmetal. Its electron configuration is 1s2. There are energy levels and they are s, p, d and f. The s level means that its maximum number of electrons is only 2.
H= energy of product minus energy of reactant
H is endothermic and positive when heat is absorbed
H is exothermic and negative when heat is released
You forgot to attach the diagram but I have an idea of what it might look like. So since the energy of reactant is at a lower level and energy of product is at a higher level, the reaction will be positive.
Answer: C. The difference of the energy of the reactants and the energy of the products.
Mass of water required = 64.42 g
<h3>Further explanation</h3>
Given
Reaction
6CO2 + 6H2O → C6H12O6 + 6O2
157.35 g CO2
Required
mass of water
Solution
mol CO₂ = mass : MW CO₂
mol CO₂ = 157.35 g : 44.01 g/mol
mol CO₂ = 3.575
From the equation, mol ratio CO₂ : H₂O = 6 : 6, so mol H₂O = mol CO₂=3.575
Mass H₂O = mol x MW H₂O
mass H₂O = 3.575 x 18.02
mass H₂O = 64.42 g
Heat of combustion ...................................................................