DiPhosphorus pentoxide or pentaoxide
Answer:
The molecular formula lists the symbol of each element within the compound followed by a number (usually in subscript). The letter and number indicate how many of each type of element are in the compound. If there is only one atom of a particular element, then no number is written after the element.
A bond is a force of attraction between atoms. They are mainly fthree types of bonds namely; ionic bond, which involves transfer of electrons between a metal and a non metal, covalent bond which occurs between non metal atoms by sharing of electrons, metallic bond which is a bond in the metal structure between metal atoms and the sea of electrons. in this case carbon and hydrogen are non metals hence they will have a covalent bond between their atoms.
Answer:

Explanation:
mass of Fe = 55.85 g
Molar mass of Fe = 55.85 g/mol
<u>Moles of Fe = 55.85 / 55.85 = 1</u>
mass of Cl = 106.5 g
Molar mass of Cl = 35.5 g/mol
Moles of Cl = 106.5 / 35.5 = 3
Taking the simplest ratio for Fe and Cl as:
1 : 3
The empirical formula is = 
Explanation:
1. Thermochemical equation is balance stoichiometric chemical equation written with the phases of the reactants and products in the brackets along with the enthalpy change of the reaction.
The given correct thermochemical reactions are:


2. Phase change affect the value of the enthalpy change of the thermochemical equation. This is because change in phase is accompanied by change in energy. For example:


In both reaction phase of water is changing with change in energy of enthalpy of reaction.