Reactions of Metals with Acids

Study Notes

Metals react with acids to produce salt and hydrogen gas:
- Metal (M) + Acid (HX) → Salt (MX) + Hydrogen Gas (H2)
Reactivity of metals with acids depends on the metal's position in the reactivity series:
- More reactive metals (e.g., sodium, magnesium) react vigorously with acids
- Less reactive metals (e.g., copper, silver) do not react with acids
Examples of reactions:
- Zinc (Zn) + Hydrochloric Acid (HCl) → Zinc Chloride (ZnCl2) + Hydrogen Gas (H2)
- Magnesium (Mg) + Sulfuric Acid (H2SO4) → Magnesium Sulfate (MgSO4) + Hydrogen Gas (H2)

Acids are substances that donate H+ ions (protons)
Bases are substances that accept H+ ions (protons)
Acid-base reactions involve the transfer of H+ ions between acids and bases
pH is a measure of the concentration of H+ ions in a solution:
- pH = -log[H+]
- pH 7: neutral solution (equal concentrations of H+ and OH- ions)
- pH < 7: acidic solution (higher concentration of H+ ions)
- pH > 7: basic solution (higher concentration of OH- ions)

Indicators are substances that change color in response to changes in pH
Indicators are used to determine the pH of a solution
Examples of indicators:
- Litmus: red in acidic solutions, blue in basic solutions
- Phenolphthalein: colorless in acidic solutions, pink in basic solutions

pH scale is a logarithmic scale that measures the concentration of H+ ions in a solution
pH scale ranges from 0 to 14:
- pH 0-1: strongly acidic
- pH 2-3: acidic
- pH 4-5: weakly acidic
- pH 6-7: neutral
- pH 8-9: weakly basic
- pH 10-11: basic
- pH 12-14: strongly basic
pH scale is used to classify substances as acidic, basic, or neutral.

Metals react with acids to produce salt and hydrogen gas, following the equation: Metal (M) + Acid (HX) → Salt (MX) + Hydrogen Gas (H2)
Reactivity of metals with acids depends on the metal's position in the reactivity series, with more reactive metals (e.g., sodium, magnesium) reacting vigorously and less reactive metals (e.g., copper, silver) not reacting
Zinc reacts with hydrochloric acid to produce zinc chloride and hydrogen gas: Zn + HCl → ZnCl2 + H2
Magnesium reacts with sulfuric acid to produce magnesium sulfate and hydrogen gas: Mg + H2SO4 → MgSO4 + H2

Acids are substances that donate H+ ions (protons), while bases are substances that accept H+ ions (protons)
Acid-base reactions involve the transfer of H+ ions between acids and bases
pH is a measure of the concentration of H+ ions in a solution, calculated as pH = -log[H+]
A pH of 7 is neutral, with equal concentrations of H+ and OH- ions
A pH below 7 is acidic, with a higher concentration of H+ ions
A pH above 7 is basic, with a higher concentration of OH- ions

Indicators are substances that change color in response to changes in pH, used to determine the pH of a solution
Litmus is an indicator that is red in acidic solutions and blue in basic solutions
Phenolphthalein is an indicator that is colorless in acidic solutions and pink in basic solutions

The pH scale is a logarithmic scale that measures the concentration of H+ ions in a solution
The pH scale ranges from 0 to 14, with 0-1 being strongly acidic, 2-3 being acidic, 4-5 being weakly acidic, 6-7 being neutral, 8-9 being weakly basic, 10-11 being basic, and 12-14 being strongly basic
The pH scale is used to classify substances as acidic, basic, or neutral