CALCULATING RATE

How is rate calculated

rate = amount of reactant / time

rate = moles / time

What are the units for rate of reaction

mass/time

volume/time

moles/time

Name three common ways of measuring rate

Loss in mass of reactant

Volume of gas produced

Time for solution to turn opaque

How can you measure the rate by monitoring mass loss

Place reaction flask on balance

A gas is given off

Record decrease in mass in time intervals

Plot a graph of mass to time

How can you measure the rate by monitoring volume of gas

Connect gas syringe to reaction flask

Measure volume of gas formed in time intervals

Plot a graph of volume to time

How can you measure the rate by monitoring disappearance of a cross

Take a piece of paper w/ a cross

Put reaction flask on the cross

Mix reagents

Measure how long it takes for a cloudy mixture to conceal a cross

How do you find a rate of reaction at some time from a graph of amount of reactant vs time

Pick a point corresponding time

Find the tangent to the curve

The tangent is the gradient of this graph