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Equilibrium & Acid + Bases. It’s gonna be lots of fun…. Example Equilibrium Equations. Equilibrium equations are constantly making products and reactants to stay at a specific equilibrium. N 2 + 3 H 2 ←→ 2 NH 3 (ΔH = −92.22 kJ· mol −1 ) 2 H 2 (g) + N 2 (g) ←→ N 2 H 4 (g).
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Equilibrium & Acid + Bases It’s gonna be lots of fun…
Example Equilibrium Equations Equilibrium equations are constantly making products and reactants to stay at a specific equilibrium. N2 + 3 H2 ←→ 2 NH3 (ΔH = −92.22 kJ·mol−1) 2 H2(g) + N2(g) ←→ N2H4(g)
Le Chatelier Principals on changing equilibrium • Temp. • Pressure • Concentration • Catalyst (Kind of)
N2 + 3 H2 ←→ 2 NH3 (ΔH = −92.22 kJ·mol−1) • Temp would shift to the left • Increased pressure would shift to the side with least amount of moles of gas; products for this one. • Increased concentration will shift to the opposite side of increased concentration. • Decreased concentration will shift to the same side to replace what’s lost.
Write a K Expression • N2 + 3 H2 ←→ 2 NH3 K= [NH3]2 --------------- [N] x [H2]3
Magnitude of K • K<1, means there are more reactants than products. • K>1, means there are more products than reactants. • K=1, products are equal to the reactants.
Haber Process (use in equilibrium) • N2 + 3 H2 → 2 NH3 (ΔH = −92.22 kJ·mol−1) • Challenge that they’re addressing is to produce a high yield of Ammonia in a short amount of time. • Add a high amount of pressure → shifts to side with less moles of gas (ammonia in this case) • Higher temperature less yield, shifts to products.
Acid/ Base • PH scale 0-14 (0-7 acid 7-14 base) • Acid donates hydrogen ions • Base accepts hydrogen ions • Dissociation ions separate into smaller particles ions in a reversible manner • Full dissociation of ions molecule breaks in to the corresponding ions.
Conductivity/ reaction/ ph • strongly conducts electricity contains a large number of ions and is called a strong acid or base. • conducts electricity only weakly contains only a few ions and is called a weak acid or base. • stronger acid / base will produce faster reactions • A change of 1 in the pH scale represents a 10 times change in the acidity or basicity of the solution (because it's a log scale). pH = - log [H+]
properties of acid base with metal and carbonates. Reaction of acids with metal hydroxides or metal oxides : Makes a salt + water, HCl + NaOH -> H2O + NaCl. Reaction of acids with metals: Makes a salt + hydrogen 2HCl + Mg -> MgCl2 + H2. Reaction of acids with carbonates: Makes a salt + water + carbon dioxide 2HCl + CaCO3 -> CO2 + H2O + CaCl2.
Properties of acids and bases acid • They dissolve in water to give a solution with pH less than 7 • They react with bases to give a salt and water • colours with indicators (Red Orange) base • They dissolve in water to give a solution with pH more than 7. • They react with acids to give a salt and water • colours with indicators (blue green)
Bronsted Lowry-Lewis Bronsted Lowry looks at acidity from the point of view of hydrogen ions. the acid is what release a hydrogen ion. the bases is what accept a hydrogen ion. Lewis electron pairs necessary to bond to the hydrogen ions and extends the concept of acidity to include any species that is able to accept an electron pair. A Lewis base is available electron pair.
formula for conjugate acid base bronsted lowry CH3COOH + H2SO4 CH3COOH2+ + HSO4- On the left hand side it is the sulphuric acid that donates the proton. It is behaving as an acid. Its conjugate base is on the other side of the equation that would accept the proton to go in the reverse direction. HCl + NH3 NH4Cl reaction between ammonia gas and hydrogen chloride the hydrogen chloride transfers a hydrogen ion to the ammonia making an ammonium ion. the ammonia is behaving as a Brønsted Lowry base by accepting a proton. The hydrogen chloride is a Brønsted-Lowry acid for (donating) that proton