The molar mass of water is calculated as follows: H (1 g/mol) x 2 + O (16 g/mol) = 18 g/mol.

Molar mass of NaCl = 58.44 g/mol. Moles needed = 0.2 M * 0.5 L = 0.1 moles. Mass = moles * molar mass = 0.1 * 58.44 g = 5.844 g.

The reaction between KOH and HCl is 1:1. Therefore, 0.1 moles of HCl will require 0.1 moles of KOH.

Using the Henderson-Hasselbalch equation: pH = pKa + log([A-]/[HA]). pKa of acetic acid is approximately 4.76. Since [A-] = [HA], pH = 4.76.

H2SO4 dissociates to give 2 H+ ions. Moles of H2SO4 = 0.1 M * 0.050 L = 0.005 moles. Therefore, moles of NaOH required = 0.005 moles * 2 = 0.01 moles.

The reducing agent donates electrons and is oxidized in the process.

Gangue refers to the waste material that is separated from the desired metal during the extraction process.

When a transition metal acts as a reducing agent, it donates electrons, resulting in a decrease in its oxidation state.

When a transition metal acts as an oxidizing agent, its oxidation state increases as it gains electrons.

The oxidation state of the reducing agent decreases as it donates electrons.

Oxidizing agents are reduced as they gain electrons during redox reactions.

The oxidizing agent is reduced as it gains electrons during the reaction.

Calcination refers to the heating of ores in the absence of air to drive off volatile substances.

Flux is a substance added to a metallurgical process to promote melting and help remove impurities.

Gangue refers to the waste material that is separated from the desired metal during the extraction process.

Reduction refers to the gain of electrons, which is essential in the extraction of metals.

Roasting a sulfide ore involves heating it in the presence of oxygen to convert it into an oxide, which is a necessary step for further extraction of the metal.

Roasting sulfide ores involves heating them in the presence of oxygen to convert them into oxides, which can then be reduced to extract the metal.

The oxidation state refers to the charge of an atom in a molecule, indicating its degree of oxidation.

When a transition metal acts as a reducing agent, it loses electrons and is oxidized.

The oxidation state of manganese decreases from +7 in MnO4- to +2 in Mn2+.

Iron is commonly used as a reducing agent in various redox reactions.

Limestone is added to form slag, which helps remove impurities during the extraction of iron.

Limestone is used as a flux in the extraction of iron to remove impurities as slag.

A flux is used to remove impurities from the metal during the extraction process.

Hydrogen acts as a reducing agent in the extraction of metals from their ores, such as in the reduction of metal oxides.

In HCl, hydrogen can act as a Lewis acid by accepting an electron pair.

In NaH (sodium hydride), hydrogen has an oxidation state of -1.

In the complex [Fe(H2O)6]2+, water (H2O) acts as a ligand, coordinating with the iron ion.

Hydrogen reduction is a process where hydrogen gas is used to reduce metal ores to their metallic form.