Ch.4 - Chemical Quantities & Aqueous ReactionsWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Solution: How many moles of hydrogen gas would be produced for every mole of magnesium added into the HCl solution? Reaction of magnesium metal with hydrochloric acid. The metal is readily oxidized by the acid, producing hydrogen gas, H2(g), and MgCl2(aq).

Problem

How many moles of hydrogen gas would be produced for every mole of magnesium added into the HCl solution?

A series of photographs shows the overall reaction of the reactants 2 HCl (aqueous) plus Mg (solid) going to the products H2 (gas) plus MgCl2 (aqueous). The oxidation numbers in the reactants are: H, positive 1; Cl, negative 1; Mg, 0.  The oxidation numbers in the products are: H, 0; Mg, positive 2; Cl, negative 1. In the first photograph, a spiral of solid Mg is added to a solution of H+ and Cl- ions. In the second photograph, solid Mg is oxidized (loses electrons) and H+ (aqueous) is reduced (gains electrons).  The solution bubbles as the magnesium spiral is dissolved. In the third photograph, the Mg2+ ions are in solution and some H2 gas has been produced.


Reaction of magnesium metal with hydrochloric acid. The metal is readily oxidized by the acid, producing hydrogen gas, H2(g), and MgCl2(aq).