📖 Factors Affecting Reaction Rate▼

The rate of a chemical reaction is defined as the speed at which reactants are converted into products. Collision theory states that for a reaction to occur, particles must collide with sufficient energy (activation energy) and correct orientation.

Concentration

Higher concentration means more particles in a given volume, leading to more frequent successful collisions. Rate increases.

Temperature

Higher temperature increases kinetic energy. Particles move faster, colliding more often and with greater force. Rate increases.

Surface Area

Smaller pieces (powder vs chunks) expose more surface area to the other reactants, allowing more simultaneous collisions. Rate increases.

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⚠️ Safety

  • Dilute & concentrated HCl are corrosive — wear goggles and gloves; wipe spills and rinse skin with plenty of water.
  • Zn + HCl releases hydrogen (H₂), which is flammable — keep away from flames; do not seal the flask.
  • Na₂S₂O₃ + HCl releases sulphur dioxide (SO₂), a toxic, choking gas — work in a fume cupboard / well-ventilated area, especially for asthmatics.
  • Heating the thiosulphate mixture: handle warm glassware with care and use a water bath, not a direct flame.
Reaction: Zn + 2HCl → ZnCl₂ + H₂↑
Dilute HCl
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Time: 0.0s
Conc. HCl
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Lab Journal
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