Acids, Bases and Alkali Flashcards
What is an acid?
A substance that releases hydrogen ions (H⁺) when dissolved in water.
Examples: HCl, H₂SO₄, HNO₃. pH: Less than 7.
What is a base?
A substance that can neutralize an acid to form a salt and water.
Examples: Metal oxides (e.g., CuO), metal hydroxides (e.g., NaOH), and ammonia (NH₃).
What is an alkali?
A base that dissolves in water to release hydroxide ions (OH⁻).
Examples: NaOH, KOH, NH₃ (aqueous). pH: Greater than 7.
What is a salt?
A compound formed when the hydrogen ion of an acid is replaced by a metal ion or ammonium ion (NH₄⁺).
Examples: NaCl (sodium chloride), CuSO₄ (copper(II) sulfate).
What are the properties of acids?
Sour taste, turn blue litmus red, react with metals, bases, and carbonates to form salts.
What is the reaction of an acid with a metal?
Acid + Metal → Salt + Hydrogen.
Example: 2HCl + Mg → MgCl₂ + H₂.
What is the reaction of an acid with a base?
Acid + Base → Salt + Water (Neutralization).
Example: H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O.
What is the reaction of an acid with a carbonate?
Acid + Carbonate → Salt + Water + Carbon Dioxide.
Example: 2HCl + CaCO₃ → CaCl₂ + H₂O + CO₂.
What is the reaction of an acid with ammonia?
Acid + Ammonia → Ammonium Salt.
Example: HCl + NH₃ → NH₄Cl.
What are the properties of bases/alkalis?
Bases neutralize acids, alkalis are soluble bases, turn red litmus blue, have a slippery feel.
What is the reaction of an alkali with an acid?
Alkali + Acid → Salt + Water (Neutralization).
Example: NaOH + HNO₃ → NaNO₃ + H₂O.
What is the reaction of an alkali with an ammonium salt?
Alkali + Ammonium Salt → Salt + Ammonia + Water.
Example: NaOH + NH₄Cl → NaCl + NH₃ + H₂O.
What is the reaction of an alkali with a metal ion solution?
Alkali + Metal Ion Solution → Precipitate.
Example: CuSO₄ + 2NaOH → Cu(OH)₂↓ + Na₂SO₄.
What is neutralization?
Combining H⁺ ions from the acid with OH⁻ ions from the alkali to form water.
Example: H⁺ + OH⁻ → H₂O.
What does the pH scale indicate?
pH < 7: Acidic, pH = 7: Neutral, pH > 7: Alkaline.
What is the litmus indicator?
Red in acid, blue in alkali.
What is the methyl orange indicator?
Red in acid, yellow in alkali.
What is the phenolphthalein indicator?
Colorless in acid, pink in alkali.
What is the universal indicator?
A range of colors showing different pH levels.
How are salts prepared?
By reacting an acid with metals, insoluble bases, carbonates, or alkalis.
What is the method of salt preparation using a metal?
Add excess metal to acid until bubbling stops, filter, and evaporate the solution.
Example: Zn + 2HCl → ZnCl₂ + H₂.
What is the method of salt preparation using an insoluble base?
Warm the acid, add excess base, filter, and evaporate water.
Example: CuO + H₂SO₄ → CuSO₄ + H₂O.
What is the method of salt preparation using a carbonate?
Add carbonate to acid until no more fizzing occurs, filter, and crystallize the salt.
Example: CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂.
What is the titration method for salt preparation?
Use a pipette to measure alkali, add acid from a burette, and crystallize the salt.
Example: HCl + NaOH → NaCl + H₂O.
What are the solubility rules for salts?
Soluble: Sodium, potassium, ammonium salts, all nitrates, chlorides (except AgCl, PbCl₂), sulfates (except BaSO₄, PbSO₄, CaSO₄). Insoluble: Carbonates (except Na⁺, K⁺, NH₄⁺), hydroxides (except Na⁺, K⁺, NH₄⁺).
What are precipitation reactions?
Used to prepare insoluble salts by mixing two soluble salts.
Example: React barium chloride with sodium sulfate to form barium sulfate precipitate.
