Answer:
The equation to show the the correct form to show the standard molar enthalpy of formation:
Explanation:
The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements, with all substances in their standard states.
Given, that 1 mole of 
gas and 1 mole of 
liquid gives 2 moles of HBr gas as a product.The reaction releases 72.58 kJ of heat.
Divide the equation by 2.
The equation to show the the correct form to show the standard molar enthalpy of formation:
Answer:
Explanation:
In a chemical formula, the oxidation state of transition metals can be determined by establishing the relationships between the electrons gained and that which is lost by an atom.
We know that for compounds to be formed, atoms would either lose, gain or share electrons between one another.
The oxidation state is usually expressed using the oxidation number and it is a formal charge assigned to an atom which is present in a molecule or ion.
To ascertain the oxidation state, we have to comply with some rules:
- The algebraic sum of all oxidation numbers of an atom in a neutral compound is zero.
- The algebraic sum of all the oxidation numbers of all atoms in an ion containing more than one kind of atom is equal to the charge on the ion.
For example, let us find the oxidation state of Cr in Cr₂O₇²⁻
This would be: 2x + 7(-2) = -2
x = +6
We see that the oxidation number of Cr, a transition metal in the given ion is +6.
D. It gives the same results when experiments are repeated
Answer: 8 electrons
Explanation: Valence electrons are the electrons in the outermost shell of an atom and they are important in chemical reactions.
Atoms are <em>happy</em> when they follow the octet rule which states that 2 electrons can go in the first shell and 8 electrons can go in the other shells.
Electrons are happy when they have a full outer shell which usually needs to be 8 electrons. However, some of the smaller elements like helium are happy because they can hold a max of 2 electrons and helium has 2 electrons since it has 2 protons in its core as well as 2 electrons in its energy levels.
