Rates of Reaction Flashcards
Why is it important to keep fermentation in anaerobic (no oxygen) conditions?
Oxygen converts ethanol into ethanoic acid (vinegar) which doesn’t taste nice.
How do you find the rate of reaction on a curved graph?
Find the gradient of the tangent.
If magnesium reacts with hydrochloric acid which of the following will speed up the reaction: a. Lower temperature b. Bigger pieces of magnesium c. More concentrated acid d. More dilute acid e. Magnesium powder f. Increasing the temperature
a. slower b. slower c. faster d. slower e faster f faster
How do you find the rate of reaction using a gradient?
Change in Y
Change in X
Why are catalysts important in industry?
+Reactions are quicker +They happen at lower temperatures +So it is cheaper to make product
If magnesium reacts with hydrochloric acid which of the following will speed up the reaction: +a) Lower temperature +b) Bigger pieces of magnesium +c) More concentrated acid +d) More dilute acid +e) Magnesium powder +f) Increasing the temperature
+a) slower +b) slower +c) faster +d) slower +e) faster +f) faster
What is an endothermic reaction?
A reaction which takes in energy from the surroundings.
Shown by a fall in temperature of the surroundings.
What are precipitates?
Insoluble solids which form when two solutions are mixed together.
What is an exothermic reaction?
A reaction which give out energy to surroundings.
Shown by a rise in temperature of the surroundings.
Why does increasing pressure of a gas increase the rate of reaction?
- The higher the pressure the faster the reaction.
- Particles are closer together in a decreased volume
- So there there would be more frequent collisions.
What rection is this?
An exothermic reaction
What does a catalyst do to the activation energy?
The catalyst lowers the activation energy. + this means many more collisions are likely to be successful.
Why are catalysts important in the industry?
They help substances to react quickly at lower temperatures and pressures than would otherwise be needed. This saves money.
What is an anomalous result?
+Does not fit on best line of fit +Higher or lower than expected
Describe how the volume of gas changes
Volume of gas increases quickly in first 3 to 4 minutes Then slows down At 8 minutes no more gas made
What is a catalyst?
+A substance that speeds up chemical reactions without getting used up in the process or being chemically changed.
What is the rate of reaction?
How fast a reaction takes place.
What is MEXO BENDO
Making bonds = Exothermic
Breaking bonds = Endothermic
Why does increasing concentration of a solution increase the rate of reaction?
- The higher the concentration the faster the reaction.
- Increasing the concentration means there are more particles of reactant in the same volume
- So there would be more frequent collisions.
What 2 things need to occur for a reaction to take place?
+ Must Collide +Must have enough energy to react (for bonds to be made/broken)
What are enzymes?
Biological catalysts - catalyse chemical reactions in living cells (eg respiration, photosynthesis,protein synthesis)
What does it mean if a reaction is slow in terms of activation energy?
It means that very few of the collisions occurring have the activation energy required for the reaction to happen. When most of the collisions occur the particles will just bounce off of each other.
What does a higher surface area mean?
A higher rate.
Give 4 factors that affect rate of reaction.
+Temperature +Concentration +Surface area +Catalyst
