What is Blackman's law of limiting factors?
GeneralClass 12AllAnswered 27 Mar 2026
Answer
Blackman's Law of Limiting Factors (1905):
Statement: "If a chemical process is affected by more than one factor, then its rate will be determined by the factor which is nearest to its minimal value. It is this factor which directly affects the process if its quantity is changed."
Application to photosynthesis:
Example at dawn:
- Low light intensity → Light is limiting factor
- Increasing CO₂ has NO effect
- Increasing light DOES increase photosynthesis rate
Example at noon:
- High light, low CO₂ → CO₂ is limiting factor
- Increasing light has NO further effect
- Increasing CO₂ DOES increase rate
Graphical representation: Photosynthesis rate plateaus when the limiting factor reaches saturation.
Suggested Q&A
General · Class 12- GeneralClass 12Electric Field at Centre of Ring with Non-Uniform Charge Distribution. Four quadrants carry linear charge densities: +2λ, −2λ, +λ, −λ. Find electric field at centre.
- GeneralClass 12P°(hexane) = 408 Torr, P°(heptane) = 141 Torr. x(hexane) = 0.300. Find Y₆ and Y₇.
- GeneralClass 122N₂O₅(g) → 4NO₂(g) + O₂(g). Initial P = 50 mmHg; P at 30 min = 87.5 mmHg. Find P at 60 min.
- GeneralClass 12What is the difference between psychosis and neurosis?
- GeneralClass 12What is the difference between prism and a pyramid?
- GeneralClass 12What is the difference between phrase and clause?