Most transition metals can exist in more than one oxidation state, and as such, can form oxides with different formulas. If a basic solution containing 1.89 g of dissolved copper(II)chloride dihydrate (molar mass = 170.48 g/mol) is reacted with excess hydrazine, N2H4, a red form of copper oxide is created. If that solid is isolated, it has a mass of 0.79 g after drying.  What is the formula of this copper oxide?
Did the oxidation state of copper change during this reaction?

- The formula of the formed copper oxide is Cu₂O

- The oxidation state of copper does change from (II) to (I), because copper is reduced.

Explanation:

Hydrazine (N₂H₄) is a well known reducing agent, so it reduces copper(II)chloride (CuCl₂). The oxidation state of Cu in CuCl₂ is +2:

CuCl₂ → Cu²⁺ + 2 Cl⁻

Thus, when Cu²⁺ is reduced to an oxide, it is formed copper(I) oxide (Cu₂O), which is a red solid. According to this, we can conclude:

- The formula of the formed copper oxide is Cu₂O.

- The oxidation state of copper does change from (II) to (I), because copper is reduced.

vanderwaal's forces of attraction are the electrostatic intermolecular forces that exist in a molecule due to the temporary or permanent dipoles that are developed in a molecule. in , the major intermolecular forces are dipole-dipole interactions as the molecule is polar (bent structure). so the vanderwaal's forces of interaction in between molecules are the permanent dipole-dipole interactions that develop due to the dipole that exists in between the polar h - s bond. the positively charged hydrogen atom is attracted towards the negative end of the dipole that is sulfur of the adjacent molecule. therefore, these forces of attraction are relatively stronger than that of london dispersion forces that exist in non polar molecules.

the dependant variable is spilled water

the independent is the heat