Loading…
Loading…
GCSE Chemistry · key term
The rate of reaction at one particular moment, found from the gradient of a tangent to a curve.
Used by Edexcel and OCR
Specification 7.5 · Paper 2
Revise: Graph InterpretationTo estimate the instantaneous rate at a chosen time, draw a tangent whose direction matches the curve at that point. Choose two well-separated, convenient points on the tangent, calculate its gradient, and attach the correct units.
Specification CM5.2iii, C5.2b · Paper 2 (Foundation), Paper 4 (Higher)
The rate at one particular moment, found from the gradient of a tangent to a curve.
Revise: Gradients as RateAt 20 s, the tangent follows the curve's local direction, so its gradient estimates the instantaneous rate at that moment. The gradient can be calculated from two convenient, well-separated points anywhere on the tangent.
The rate at one particular moment, represented by the gradient of a tangent to a curve.
Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)
The rate at one particular moment during a reaction.
Revise: Interpreting rate graphsTo find the instantaneous rate at one chosen time, draw a tangent to the curve at that point. The tangent should follow the direction of the curve locally.
For a curve, do not find the instantaneous rate using two points on the curve either side of the stated time; draw a tangent at that time and calculate its gradient.
For an instantaneous rate, draw the tangent at the specified point and use two well-separated points on the tangent—not points on the curve—to calculate its gradient.
Create a free account to read GCSE Chemistry revision notes for your exam board and track your progress.