Chemistry Balancing, Predicting, Formulas Flashcards
starting substances
reactant
Process by which substances collide with enough energy
that new bonds are formed between atoms, thus creating
new substances
chemical reaction
ending substances
product
dissolved in water
aqueous
Differentiate between physical and chemical change.
Physical changes do not impact a substance’s identity (state of matter change)
Chemical changes result in a new substance from a chemical reaction occurring (burning)
Explain the collision theory
Reacting particles must collide with enough energy for a chemical reaction to occur
List several signs that can provide evidence that a
chemical reaction has occurred.
Release of light or heat, sudden color change, odor
change, gas released, formation of a precipitate
Explain the Law of Conservation of Mass and how
it relates to chemical reactions.
Matter cannot be created or destroyed in a system – it can
only change forms.
So even in a chemical reaction, the mass of the reactants
should equal the mass of the products.
Differentiate between coefficients and subscripts in
a chemical reaction.
Coefficients: are placed in front of a substance and
represent ratios of reactants to products. They are used
for balancing reactions and can be changed.
Subscripts: are the small numbers within each chemical
formula that show the ratio of atoms in a compound. They
cannot be changed because changing them changes the
identity of the substance.
List the number of atoms of each element in the compound:
Mg3 (PO4)2
Magnesium - 3
Phosphorous - 2
Oxygen - 8
Be able to balance equations:
NF3 —> N2 + F2
2NF3 —> N2 + 3F2
Write the balanced chemical equation for the
following reaction: Solid aluminum reacts
with oxygen gas to create solid aluminum
oxide.
4Al (s) + 3 O2 (g) —> 2Al203 (s)
Chemical reactions can be classified into 5 categories:
Synthesis
Decomposition
Combustion
Single Replacement
Double Replacement
Which process is this?
2 or more reactants combine to form a new compound.
A + B = AB
When an element combines with oxygen, it produces an oxide (a binary compound with at least 1 atom of oxygen)
Synthesis
Which process is this?
1 reactant produces 2 or more simpler compounds.
AB = A + B
Most only take place when energy (in the form of heat or electricity) is added.
Decomposition
the decomposition of a substance
by an electric current
electrolysis
Which process is this?
When a substance reacts with oxygen.
Often produces a lot of energy in the form of heat and light
Most occur with a hydrocarbon and produce carbon dioxide and water.
Combustion
a compound made of carbon and
hydrogen
hydrocarbon
Which process is this?
When one element replaces an element like it
in a compound.
A + BC = B + AC
Many take place in an aqueous solution
The most reactive metals can react with water to produce metal hydroxides and hydrogen.
Single Replacement
Which process is this?
When the ions of two compounds exchange places in an aqueous solution to form 2 new compounds.
AB + CD = AD + CB
One of the resulting products is usually a:
Precipitate: an insoluble solid that forms from the ions
of two aqueous compounds
Ex. NaCl(aq) + AgNO3(aq) 🡪 AgCl(s) + NaNO3(aq)
Insoluble gas (seen as bubbles given off)
Ex. FeS(s) + 2HCl(aq) 🡪 H2S(g) + FeCl2(aq)
Molecular compound like water
Ex. HCl(aq) + NaOH(aq) 🡪 NaCl(aq) + H2O(l)
Double Replacement Reaction
Aka acid-base reaction
When an acid and a base react to form water and a salt
Neutralization reaction
a substance that makes H+ ions when dissolved in water
acid
a substance that makes OH- ions when dissolved in water
base
an ionic compound made from the cation of a base and an anion from an acid
salt
a list of elements in the order in which they will easily undergo certain chemical reactions
activity series
Metals that have a greater activity means they ______ e- more easily.
lose
Nonmetals that have a greater activity means they _____ e- more easily.
gain
Can elements replace any element above them or below them?
below
