Reaction of Practicals Flashcards
NOTE: Measuring gas production
We can see how changing the surface area affects rate of reaction by measuring how much gas is produced when marble chips (calcium carbonate) of different surface areas react with hydrochloric acid.
Set up equipment as shown. Make sure the measuring cylinder is full with water.
Place in a known mass of marble chips.
The surface area is the independent variable.
Pour in a known concentration and excess volume of acid.
Start the timer.
Record volume of gas produced every 5 seconds.
This is the dependent variable.
Plot a graph of time against volume of gas.
Draw a curve of best fit.
Calculate the gradient to find rate at different times.
NOTE: Measuring gas production
We can see how changing the surface area affects rate of reaction by measuring how much gas is produced when marble chips (calcium carbonate) of different surface areas react with hydrochloric acid.
Set up equipment as shown. Make sure the measuring cylinder is full with water.
Place in a known mass of marble chips.
The surface area is the independent variable.
Pour in a known concentration and excess volume of acid.
Start the timer.
Record volume of gas produced every 5 seconds.
This is the dependent variable.
Plot a graph of time against volume of gas.
Draw a curve of best fit.
Calculate the gradient to find rate at different times.
In the experiment measuring rate of reaction by gas being produced, what are the dependent and independent variables?
Dependent = volume of gas produced every 5 seconds
Independent = surface area of marble chips
NOTE: Observing a colour change
We can see how changing the concentration affects rate of reaction by observing colour changes in the reaction between sodium thiosulfate and hydrochloric acid.
Set up equipment as shown. Make sure the x can be seen on a sheet of paper under the reaction vessel.
Place in solutions (except acid) in beakers.
Pour in acid with a known concentration (this is the independent variable) and press start on the stop clock.
Stop the clock when the cross cannot be seen.
The time taken is the dependent variable.
Repeat for different concentrations of acid.
Plot a graph of time against concentration of acid.
Draw line of best fit.
Calculate the gradient to find how the rate changes per increase in concentration.
NOTE: Observing a colour change
We can see how changing the concentration affects rate of reaction by observing colour changes in the reaction between sodium thiosulfate and hydrochloric acid.
Set up equipment as shown. Make sure the x can be seen on a sheet of paper under the reaction vessel.
Place in solutions (except acid) in beakers.
Pour in acid with a known concentration (this is the independent variable) and press start on the stop clock.
Stop the clock when the cross cannot be seen.
The time taken is the dependent variable.
Repeat for different concentrations of acid.
Plot a graph of time against concentration of acid.
Draw line of best fit.
Calculate the gradient to find how the rate changes per increase in concentration.
When measuring rate of reaction by colour change, when should we stop the time
the moment the cross cannot be seen
what do we need an excess amount of when measuring production of gas (rate of reaction)?
acid
