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Reaction Exam Review
Standards 4 and 5
Question | Answer |
---|---|
elements are represented by | symbols |
molecules/compounds are represented by | chemical formulas |
chemical changes/reactions are represented by | chemical equations |
equations must be ______________ (Law of Conservation of Matter) | balanced |
number behind/below the symbol or formula | subscript |
number in front of a symbol or chemical formula | coefficient |
7 diatomic molecules | hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, iodine |
what is (s) ? | solid |
what is (l) ? | liquid |
what is (g) ? | gas |
what is (aq) ? | aqueous |
what is added to balance an chemical equation: subscript or coefficent | coefficient |
why can't subscripts be changed ? | it would change the compound |
substances on the left of an equation | reactants |
substances on the right of an equation | products |
2 substances join to form one product EX: __Na + __CL2 ➡ __NaCL | synthesis |
1 substance breaking away to form 2+ products EX: __NaHCO3 ➡ Na2CO3 + CO2 + H20 | decompositon |
alone and swaps with another EX: __K + __MgBr2 ➡ __Mg + __KBr | single displacement |
one element in molecule/compound swaps with another element in molecule/compound EX: __Ba3N2 + __ CaS ➡ __Ca3N + __BaS | double displacement |
involves burning a hyrdocarbon in oxygen EX: __CH4 + __02 ➡ __ CO2 | combustion |
element alone will switch with an element if it is ____ active & ____ on the activity series | more; higher EX: __Al + __BaCl2 ➡ __Ba + __AlCl3 (not reactive: Ba is above Al) |
products of a combustion reaction | carbon dioxide & water |
products of double displacement between acid & base | salt & water |
gas identified by burning a wooden splint | carbon dioxide |
gas identified by "popping" or "barking" | hyrdogen |
gas identified by a glowing wooden splint to reignite flames | oxygen |
reaction that gives off heat | exothermic |
reaction that absorbs heat | indothermic |
amount of product IS made in a reaction | experimental/actual yield |
amount of product that COULD be made in a reaction | theoretical yield |
COMPARISON of amount of product made to what could have been made | percentage yield |
solid in solution made during an reaction | precipitate |
5 signs chemical change has occurred | produces light, color change, creates gas, temperature change, creates precipitate |
study of quantitative relationships between reactants and products in a balanced equation | stoichiometry |
reactant that runs out first in a chemical reaction | limiting reagent |
how many atoms: 2Ba(OH)2 | Ba- 2 O- 4 H- 4 |
how many atoms: 2(NH4)2SO4 | N- 2 H- 16 S- 2 O- 4 |