RP - 11.5 Rates of Reaction Flashcards
Required Practical
what is the rate of reaction
how fast reactants are turned into products
what are 4 factors that affect rate of reaction
- temperature
- concentration/ pressure
- catalysts
- surface area
what practical can we use to determine rate of reaction
determining how fast a product, such as gas, is formed
What are the steps to measure rate of reaction in a practical (using a measuring cylinder)
1) add 50cm^3 of hydrochloric acid into a measuring cylinder - do this at eye level when filling it
2) submerge the measuring cylinder in the water trough to fill it with water and stand it up upside down (stops any air bubbles)
3) clamp measuring cylinder 1cm from bottom of trough
4) feed delivery tube into bottom of cylinder
5) add magnesium to the conical flask and put the bung on top to prevent any gas escaping whilst begin the stopwatch
6) record the measurements on the cylinder ever 10 seconds
(You should see water go down the cylinder as more gas increases)
What should you expect to see in a rate of reaction practical when using a measuring cylinder
The water should go down the cylinder quickly because there is a lot of gas being produced
How do we do rate of reaction practical using a gas syringe
1) add 50cm^3 of hydrochloric acid into a measuring cylinder - do this at eye level when filling it and then put into a conical flask
2) attach gas syringe to clamp and attach delivery tube to top of it
3) place magnesium in conical flask and put bung on top and start stopwatch
4) record the measuring every 10 seconds
What should you expect to see in a rate of reaction practical with a gas syringe
When magnesium is added to the conical flask and gas is produced the syringe should start moving out
Which has a faster rate of reaction - rate of reaction practical with measuring cylinder or gas syringe
Measuring cylinder
What is the limiting reactant in a rate of reaction practical
The metal (etc magnesium)
What are 2 factors that can affect why are results aren’t accurate in rate of reaction practical
- you have to put magnesium and the bung into the conical flask whilst starting the timer all at the same time
- some hydrogen may be lost at the beginnning of the reaction
What piece of equipment would be much more precise in giving us results in a rate of reaction practical
Inverted Biurette
What is the purpose of the bung and delivery tube in Method 1(measuring cylinder)?
To prevent the escape of hydrogen gas
What is the purpose of the black paper cross in Method 2(gas syringe)?
To provide a reference point for visibility
What is the dependent variable in the investigation?
Volume of hydrogen gas produced
What is the independent variable in the investigation?
Concentration of the hydrochloric acid
