science test reactions Flashcards
What is the most important chemical reaction on earth
photosynthesis
What are the reactants in photosynthesis
water and carbon dioxide
What are the products of photosynthesis
glucose and oxygen
Why is photosynthesis so important
it produces glucose and makes breathable air for humans
Where does the largest percentage of photosynthesis take place on the earth
the ocean
What is the energy source for photosynthesis?
light energy from the sun
A reaction that requires energy to take place is called
endogenic energy
balanced equation for photosynthesis
6CO2 + 6H2O -> C6H12O6 + 6O2
What is the opposite reaction of photosynthesis called
cellular respiration
Why do organisms use cellular respiration
to generate energy
A reaction that gives off energy is called
exergonic reaction
The cell energy product of cellular respiration is called
ATP
How is combustion similar to cellular respiration
They both release energy and produce carbon dioxide and water
Why is too much combustion a problem on the earth
bec it blocks heat coming out of earth
Give 4 alternatives to using combustion as an energy source
Solar power, water energy, biofuels, and wind energy
Why is ozone important
It absorbs some radiation from the sun which protects the earth’s surface. Protects us from the ultraviolet rays
In what layer of the atmosphere is the ozone layer located
stratosphere
2 reactions that make ozone
O2 -> O + O
O + O2 -> O3
What is the energy source that makes the first reaction take place
ultra violet radiation
What type of chemical reaction is the first reaction
decomposition
What type of chemical reaction is the second reaction
synthesis
determine if something is an element, compound, or mixture
Element cannot be broken down, compound can be broken down by chemical reactions, mixture can be broken down by physical reactions
parts of a chemical equation
reactants yield products
the law of constant proportions is and how it relates to chemical formulas and chemical reactions
law of constant proportions – the numbers in a compound formula cannot be changed, ratios are constant
how was the law of constant proportions was shown in the decomposition of water lab and zinc in hydrochloric acid lab
2 hydrogens to one oxygen and the ratio stays the same
when a reaction uses up one of the reactants the reaction stops and relate this to the zinc in hydrochloric acid lab
Limiting reactant, runs out of one of two reactants, ran out of hydrochloric acid
how chemical reactions differ from physical reactions
bigger changes, minor changes, new substance, no new substance, heat change, minor heat change,
