Unit B Section 4 Flashcards
______are shown on the left side of the arrow in a chemical reaction
reactants
________are shown on the right side of the arrow in a chemical reaction
Products
Evidence that a chemical reaction occurred?(4)
Change in colour,odour,formation of solid or gas, release/absorption of energy
Reaction that absolves heat energy
Endothermic
Reaction that releases heat energy
Exothermic
which chemical reaction is melting an example of
Endothermic
what is lighting a fire an example of
Exothermic reaction
3 chemical changes involving oxygen?
Combustion, corrosion and cellular respiration
When oxygen reacts with a substance to form a new substance and release energy
Combustion
Occurs when oxygen reacts with metal (rust)
Corrosion
cells in the body; food reacts with oxygen to produce water, energy and CO2
Cellular respiration
what are reactions
chemicals that react to form products
Law of conservation of mass?
Matter is neither created or destroyed
Who is credited the discoverer for the law of conservation of mass
Antoine Laurent Lavoisier
In a chemical change, the total mass of the new substance is always the _________ as the mass of the _________ substances
Same, original
What is a closed system?
Nothing is allowed to escape, allowing us to weigh everything
What is an open system ?
Materials may escape, like gas
What is the rate of the reaction?
The speed that a chemical reaction will take place
_____ things can speed up/ slow down the rate of a reaction
4
Things that affect the rate of a reaction
- Presence of a catalyst
- Concentration of reactants
- Surface area of reactants
- temperature of reactants
2 properties of catalysts
- not consumed during chemical reactions
- speed up reactions
What are ‘catalysts’ in the human body?
Enzymes
Example of an enzyme?
Salivary amylase
The _________ the concentration of the _______ the faster the reaction.
Greater, reactants
The __________ the temperature of the __________ the slower the reaction
Lower,reactants
The __________ the surface area of the _________ the faster the reaction
Larger, reactants
