An energy diagram of a chemical reactions illustrates the changes of energy as the chemical reactions advances.
At first, the energy in the diagram is the energy of the reactants.
As the reaction goes forward, the reactants start to react forming a transition compound, with a maximum energy level on the graph. This is the hill. So the hill represents the Activation Energy.
After that, the energy starts to decrease and at the end you have the energy of the products, which may be higher or lower than the initial energy of the reactants, depending upon whether the reaction is exothermic or endothermic.
For exothermic reactions the energy level of the products is lower than the energy level of the reactants, while for endothermic reactions the energy level of the products is higher than the energy level of the reactants.
Empirical formula: The formula consist of proportions of the elements which is present in the compound or the simplest whole number ratios of atoms.
Now, molecular formula is equal to the product of n (ratio) and empirical formula.
Molecular formula = (1)
molecular formula = (given)
Since, 6 is the smallest subscript in above molecular formula to get the simpler whole number of atoms. Therefore, divide all the subscripts i.e. number of carbon atoms (12), number of hydrogen atoms (24) and number of oxygen atoms (6) by 6.
empirical formula becomes
Thus, according to the formula (1)
Hence, empirical formula of given molecular formula is
Your question is incomplete. However, I found a similar problem fromanother website as shown in the attached picture.
To solve this problem, you must know that at STP, the volume for any gas is 22.4 L/mol. So,
Moles O₂: 156.8 mL * 1 L/1000 mL* 1 mol/22.4 L = 0.007 moles
Mass calcium: 0.007 mol O₂ * 2 mol Ca/1 mol O₂ * 40 g/mol Ca =
<em> 0.56 g Ca</em>