Day 16 - Acid Rain, Day 15: Danube River, Day 15 - Neutralization, Day 14 - Acids & Bases-pH scale, Day 13 - Properties of Acids & Bases, Day 1 - 5.1 Properties & Changes (PG 175-178), Day 2: Trends in the Periodic Table, Lewis Dot Diagrams, Day 3= i...
-properties
like adjective: describes what substance is like
Changes
like verb: describes what substance is doing
-
model representing arrangement of electrons in orbits around nucleus
-Nucleus
most of atom's mass concentration in small, dense, positive core
Natural gas
mostly made of methane
Naming Rules: Binary Acids
name non metal, change ending -> "ic acid" -Ex. bromic acid b/c this acid type must be water dissolved, add "hydro -Ex. hydrobromic acid *No Names in capitals *if compound has H atom, no (aq)=typical binary covalent molecule Formulas: Binary Acids prefix "hydro"=binary No space, write symbols for H and nonmetal + charges in top right corner "Cross Over" charges *Include (aq) *No "1" *reduce *aq
covalent bond
bond results from sharing of outer electrons between non metal atoms
Acids
Ion present in solution [H]+ Reactivity with metals Product=H2 Electrical Conductivity Yes -No ions -collisions with water molecules break acid molecules apart=cations (H ions) & anions Taste Sour Feel N/A pH range pH<7 Ex. of common households contain an acid or base batteries, grapefruit, limes, lemons, vinegar Ex. of chemical formulas and names for acids and bases HCl(aq), H2S4(aq) =Aqueous solution =Sour taste =substances that react w. metals & carbonates =conduct electricity =turns blue litmus red =neutralize bases =Food preservative
Bases
Ion present in solution [OH]- Reactivity with metals N/A Electrical Conductivity YES -electrolytes=solutions good conductors of electricity Taste Bitter Feel Slippery pH range pH>7 Ex. of common households contain an acid or base drain cleaner, soaps, detergents Ex. of chemical formulas and names for acids and bases NaOH, CaOH, NaHCO3 =Conduct electricity =feel slippery =taste bitter =Ionic compounds -as water dissolved= ions released =Many hydroxides =In aqueous solutions -conduct electricity -Change colours of acid base indicators -turns red litmus blue Acid base indicators= shows solution is acidic or basic -Phenolphthalein= -acid=colourless -base=pink
Naming Ionic Compounds
Ionic compounds names= metal-> non metal"ide" Some metals can form ions with diff, charges Name compound with ionic charge (not number of ions) in Roman Numerals aft. Metal
What causes incomplete combustion?
Isn't enough oxygen to allow fuel (usually hydrocarbon to react completely with oxygen to produce carbon dioxide and water also when combustion is quenched by heat sink ie. solid surface or flame trap.
c. Explain why adding calcium oxide (lime) to acid polluted lakes only solves problem for a short term.
It is not strong enough to neutralize the acid.
State and explain pH of "clean rain"
It is slightly acidic, it's pH being about 5.6 because of CO2 and water in air react together.
Hydroxides
"OH" ending -ions made up of 1 O atom (2- charge) -1 H atom (1+ charge) =overall charge on hydroxide ion of 1-
Coefficient
# of molecules containing atoms
Acids
0-7 pH value -Lower pH=more acidic -acids form ion in solution -concentration of H ions determines solution's pH -solutions with highest H ion concentration near "0" -Greater H concentration in solution=stronger acidic properties
all acids release min of _ H ion when water dissolved
1
-ionic compounds
1&+ metal cations and 1&+ anions
- Lose electron
+ charge
-Common reactions
-...+H2 =metal, loner=won't react with cation series -CO2 (carbonic acid) will instantly decompose when produced in reaction, "POP"
Phosphorus Combustion
-2 forms: red=unreactive & white=reactive -EX. striking strip on pkg
basic solution
-7-14 -Higher pH=more basic -OH concentration ->7 =higher concentration of OH ions>H ions -solutions with basic properties (ie drain cleaners) near "14"
Double Displacement Pattern
-AB + CD-> AD + BC
Double Displacement
-Anions and cations (elements) from 2 diff. compounds/ molecules switch places = 2 entirely new compounds -2 non metals switch places
Products: Complete Combustion of Hydrocarbons
-CO2, water & energy -Fuels burn cleanly=no sooty residue
Chemical change evidence
-Colour change (new, unexpected colour) -Gas produced (bubbles, fizzing) -Precipitate forms (solid, forming from liquids) -Energy production (light, motion, sound, heat) -Irreversible
Balancing 3:2 atoms
-Cross multiply -LCM
Tips
-Do single elements last -Only whole numbers -No "1" if only 1 molecule
Writing Chemical Formulas
-EX. calcium hydroxide "hydroxide" ending=base No space, metal symbol, charge as a superscript in top right corner & hydroxide ion, & charge as superscript in top R corner Ex. Ca2+OH1- 3. "crossover" -Notes: Hydroxide ion= 1 item, subscript from metal must be counted for entire ion -Brackets around hydroxide ion (ONLY IF NEEDED) -ex. +1 Ion needed -EX. CA (OH)2
Making Ionic Compounds From Elements
-Elements (metal + non metal) can react=ionic compound -metals lose electrons=cations -b/c metal's hold on VE=weak =non metals gain electrons=anions +non metal attracts metal's electrons strongly =all ions have sam stable, filled VE -aft. + &- ions from diff. elements attract each other=compounds -ionic compounds=1&+ metal cations and 1&+ anions -ionic bond=simultaneous strong attraction of + & - ions in ionic compound
Fire?
-Energy produced and heat and light (-Rapid combustion is form of combustion in which large amounts of heat and light energy are released, which often results in a fire.)
4 combustion uses?
-Fuel utilization in domestic and industrial heating -steam production for industrial processes -electric power generation -waste incineration
Chemical Changes clues
-Generally irreversible (excep. ex=rechargeable batteries) -new colour appears -solid material (precipitation) forms in liquid -heat/light produced/absorbed -gas bubbles forme
Hydrogen Combustion
-H2 reacts/burns with O2= water: 2H2+O2-> 2H2O +energy -H2 as fuel=source: water -decomposition reaction to produce H2 from water= combustion reaction reverse: 2H2O+energy-> 2H2+O2 -Energy on reactant side usually from electricity -pro fuel: burns clean, only produces water & energy, endless water supply -cons: Energy, A$A$engines, explosive gas
Bases Types
-Hydroxides -Ammonia
In Ionic Compounds...
-In reaction non metal atoms pull electrons away from metal atoms -Metal ions:non metal ions (ratio) depends on number of electrons each ion gains/losses -alternating -No individual compound particle: always consists of many metal & non metal ions -Some water soluable -dissolve=ion separation -water molecules surround each ion +molecules arrange so O atoms attracted to cations & H atoms to anions =no rejoining
Single Displacement Pattern
-M= metal: M+AB-> MB+A & N=non metal: N +AB-> AN+B
Displacement Reactions in Mining
-Metals rarely occur naturally as pure elements -ores= metals & other elements=rock deposits -smelting/in smelter (factory) =processing nickel ore -nickel sulfide to nickel oxide -nickel oxide burned with carbon=pure nickel & lethal CO2
Acids reaction with...
-Metals=H2 -Carbonates =bubbles of carbon dioxide gas -Ex. Vinegar & baking soda to unblock a sink
Properties
-Most have high melting points -hard brittle electrolytes: dissolve in water=solutions that conduct electricity -Most form 3D crystals with many of each kind of ion in fixed ratio held together by opposite charges -Hard as solids -Does not conduct as solid -these ions improves conductivity of water -pure water=poor conductor -tap,lake & sea water contain ions from diff. sources (ie. minerals -maybe solutions only if ions are free to move
Oxyacids
-Polyatomic ions related -formulas differ only by 1/1+ H ions -identify by H atom at beginning & O atom at end -Ex. H2SO4 (sulfuric acid) -NO (AQ) AT END OF FORMULA -not required -still an acid
Decomposition
-Reverse of synthesis -When 1/+ large/complex chemical compounds break up to form 2 or more simpler/smaller elements/compounds Usually absorb energy (ie thermal/electrical energy) from external source (-Energy converts reactants to products)
MULTIVALENT Ions
-Some metals (mostly transition black) can = more stable in +1 method =can form ions with +1 charge -Roman Numerals -find metal original charge=undo/unreduce Crossover CHeck non metal charge Multiply if not
Binary Acids
-TYpically identify by H atom in front of formula -EX. HCl (aq) -H ions give acids their properties -begins with H, followed by aq -shows properties only when water dissolved -Ex. HCl inhaled=water dissolved in throat & lungs=highly corrosive hydrochloric acid NOT ALWAYS CASE -binary compound with H atom to be "acid" must dissolve in water -identify by (aq)=aqueous, dissolved in water
Single Displacement
-When element replaces less reactive metal cation in compound or nonmetal replaces less reactive anion=new compound & new element -Ionic compound & metal= always cation displaced -may occur when metals placed in acids
Acids
-b/c H atoms, acids ACT like ionic compounds -covalent & will separate into ions, liberating H ions when dissolved in H2O -One characteristic of acids=ability to conduct electricity -free ions presence=allows electrons to flow -evidence supporting idea acids dissociate into individual ions in solution
Chemical Spills
-caustic soda (sulfuric acid + sodium hydroxide) most widely used industrial chemicals -CAO (lime) slightly upstream
-Gain electron
-charge
Bases
-compounds will release OH ions ONLY when dissolved in water -1 characteristic shared between acids & bases= ability to conduct electricity -"free ions" presence=allows electrons to flow
Properties
-covalent diff. Than ionic compounds -lower melting points -not always solid at room temp, -tend to be softer, why feeling solids -do not conduct electricity -barely dissolve
Law of conservation of mass
-in any given chemical reaction, tot. mass of reactants= tot. mass of products -Matter cannot be created or destroyed- -Mass is conserved during chemical reaction -Antoine Lavoisier
explosion?
-large release of energy from combustion reaction (-Sudden release of large quantities of gas=excessive pressure that produces loud noise=explosions)
Sulfur Dioxide
-most impt gas -clear, colourless -strong choking odour -from coal burning industry, generate electricity, mining & refining metals, fossil fuel combustion Process: more O reaction=2SO3+ water droplets=sulfuric acid
Nitrogen Oxides
-nitrogen oxides oxidized go from nitric acid=more b/c strict laws -from cars that burn fossil fuels -internal engine temp.=N2+O2->2NO -POllution control tech now reverses= NO-> N+O -some NO escapes to atmosphere =reacts w. O=2 NO -NO=Smog -NO+water=nitric acid + NO
covalent compounds
-non metal atoms -same element or different -non metals share electroencephalogram and form neutral uncharged molecules
Bonds
-only exists between two adjacent atoms -hold atoms within molecule -one or more shared pair of electrons
Human activity
-princi. Cause= sulfur and nitrogen -EX electrici generation. Factories and motor vehicles, most= coal power plants -gases carried long distances in atom. Before converted and deposited -short factory funnels= let out smoke -longer funnels= pollutants carried farther
Natural
-princip. Volcanoes and biological process that occur on land, and water bodies -major biological source of sulfur= dimethyl sulfide (CH3)2S= waste product of plants and bacteria -effects of deposits found in ancient glacial ice in remote globe areas
Natural sources
-princip. Volcanoes and biological process that occur on land, and water bodies -major biological source of sulfur= dimethyl sulfide (CH3)2S= waste product of plants and bacteria -effects of deposits found in ancient glacial ice in remote globe areas
pH And Soil
-sensitive soil pH -Diff. plants grow best in diff. soil acidity conditions -pH altered by improving growing conditions -organisms sensitive to small pH changes in environment
Antacids
-stomach digestion=hydrochloric acid -pH 1.5 -acid may irritate stomach lining=discomfort & pain -antacids neutralize =active hydroxide and carbonate compounds -milk of magnesia=typical antacid containing mgoH (base) -thick paste not very water soluble=low concentration of OH ions=no chemical burn -powdered antacids contain baking soda (sodium hydrogen carbonate) as active ingredient -acid + carbonate base=not simple double displacement =no writing equation
Combustion reactions involving elements=
-synthesis reactions: follow A + B-> AB pattern
Double and triple bonds
-two atoms share more than one pair of electrons
Chemical equations state & qualities:
-which substances are reactants -which are products -ratios of substances (& Obeys Law of Conservation of Mass)
-Binary
2 diff elements
Synthesis
2 or more simple reactants/compounds form 1/+ larger/more complex compounds
-Rings
2, 8, 8,
What was pH value at its worst?
9.65
Complete Combustion of Hydrocarbons
= uses all available fuel =lots of O2=burn completely to release contained energy -Fuels burn cleanly=no sooty residue
Soot
=carbon particles -incomplete combustion evidence (=pollution & energy waste) -Not in complete combustion (-EX. older cars poor engines & forest fires)
Hydrocarbons
=group of molecular compound (inc. propane, C3H8, methane) -only elements=hydrogen & carbon -Most originate from fossil fuels
Incomplete hydrocarbon combustion
=limited O2 supply=not all of carbon will combust -Evidence: Orange, flickering flame
Carbon Monoxide
=odourless, colourless, highly toxic gas (-Poison symptoms) -from incomplete fuel combustion in confined space (-Home EX: poorly ventilated furnace, closed garage w. running car)
Reactants
=starting chemicals -used up during reaction -Always on Left side
Synthesis Pattern
A+B->C
catalytic converter?
Device used to reduce toxicity of emissions from internal combustion engine.
-aluminum hydroxide
Antacids & water purification gel
.Explain what is meant by "It helps that the Danube is a large river with a very high volume of water"
Because the Danube is so large, with so much water, over time the content will be diluted.
Ionic Bond
Bond involving transfer of electrons from 1 atom to another=ion
Decomposition pattern
C->A+B
Equation: Incomplete hydrocarbon combustion
C^xH^y + O^2 -> CO^2(g) + H^2O(g) + C (s) + CO (g)
CaO + water-> calcium hydroxide. Write chemical equation for reaction
CaO+H2O-> Ca(OH)2
-2
alkaline earth metals: light, reactive
-Compound
Chem combo of elements
How combustion can be used to generate extricate or power a car engine?
Coal crushed into fine dust, ignited in boiler, heated tubes of water by burning fuel to generate steam at high pressure. Steam turns turbine, same pressure to push car Pistons in engine.
Skeleton/chemical Equation
Convert names to formulas -if possible, include state
General equation: Complete Combustion of Hydrocarbons
CxHy+O2->CO2+H2O+energy
c. Wet & dry deposition differ?
Dry depositions are particles or gases, while wet depositions are rain, dew, hail and snow
3.What conditions does normal rain become acid rain?
Extra acidity is formed when air particles react with pollutants.
Name 2 chemical pollutants and acids they form in water that add extra acidity to rain
Extra acidity of rain come from reaction of mostly sulfur oxides and nitrogen oxides (primary air pollutants)with water in the air to form strong acids Iike sulfuric and nitric acids
3 professionals who need to measure efficiency of combustion reactions on a regular basis
HVAC contractors, firemen and engineers
How was sludge treated? Explain how this works and what it would produce.
Hundreds of tonnes of plaster and acetic acid were powered into rivers to neutralize the alkalinity. Thus, the cone extraction of toxic metals dropped to potable water levels.
Explain why limestone has higher pH than granite lake.
Limestone does not neutralize acid as well as granite does. The bonded calcium carbonate has more calcium ions that granite, thus does not neutralize as well.
-Ionic
Metal & Non/charged atom
Hydroxide
Metal & Water
aqueous states
Most have it for ions to move
Ammonia
NH3 -H = + -N= - -why?=not to confuse so ammonia is not thought as acid
What pH is "safe" and "normal"?
Neutral 7 of water.
-18
Noble gases:so stable they rarely react with others
Subscripts
Not charges=no + or -
Subscript
Number of ions needed for Neutral compound
Word equation: Phosphorus Combustion
P4 +5O-> P4O10 +energy
Chemical equation how one of these compounds react acid precipitation?
S+ O2=SO2c3NO2 (g)+H2O(l)->2HNO3 (aq) + NO (g)
acid rain definition?
Rain or any other form of precipitation that is unusually acidic,
General Overall Word Formula:
Reactant 1 + Reactant 2 ->Product 1 + Product 2 -In both: Reactants on left, arrow points to right/products
What percentage of sulfur dioxide and nitrogen oxide emissions came from transit in 2004?
SO: <3% NO: 51% Suggest 2 things that you could do to reduce amount of acid pollutants from transit. Attaching pollution controlling tech to reverse NO release
Products: Incomplete hydrocarbon combustion
SOOT, CO2, CO, water
Other combustion reactions
Some metals react with O2 producing metal oxides - ie. MgO
4. what 2 groups of compounds are largely responsible for causing acid rain?
Sulfur dioxide and nitrogen oxides compounds.
List AND describe all adverse effects of acid rain
Surface waters and aquatic animals: damage touch as fish eggs not hatching and killing adult fish, biodiversity reduced, insects And fish life elimination. One species greatly affected, could affect entire food web/chain-Al ions washed from acidified soil to streams & lakes, damage fish gills=suffocate Soils: some microbes are unable to tolerate and are killed, enzymes are denatured (changed in shape so they can't function) . Hydronitric ions of acid rain mobilize toxins and leach away essential nutrients and minerals. -Al toxic to plants -Buffering capacity=substance ability to resist pH changes, depends on some soil to neutralize acids. More rock=higher capacities, neutralization use up buffering minerals=eventually decreases Forests and other vegetation: stunts plant growth -Soil's buffering capacity=protection, only neutralizes small a little acid=no nutrients to grow properly.- weakens > kills trees-Vulnerable to diseases, strong winds, extreme cold Human health:cause illness and premature death such as cancer and other deadly diseases. Economic Impact-lumber loss-fish stock reduction Other: damage some building materials and historical monuments and gravestones flake and are damaged
What
any precipitation(rain, snow, fog) that has become acidic from reacting with compounds in atmosphere -Any precipitation that has pH less than normal rain pH -acid rain pH= 5.6 -emissions of sulfur and nitrogen compounds -clean/Unpolluted rain=slightly acidic -CO2(l) + H2O(g)-> H2CO (aq)=carbonic acid -carbonic acid + water = some hydronium ions (H3O+) -extra acidity from reaction of primary air pollutants (mostly sulfur oxides and nitrogen oxides with water in air=strong acids) like sulfuric and nitric acid.
Which is more likely to have healthier aquatic system? Explain.
The granite, it is not as acidic.
b. Why is calcium oxide capable of neutralizing acids despite not having hydroxide ion in its formula.
The product contains hydroxide, therefore it acts as a base.
atoms in a chemical reaction
atoms separated and rearranged =atom numbers of reactant must equal atom number of each element on product side -b/c all reactant atoms still present in products
What is more at risk, the Danube, or the surrounding land? Explain.
The surrounding land because the Danube is a very large river with a very high volume of water, while the soil will take a few years to be diluted.
Explain why aluminum production produces sludge with such basic pH.
When producing aluminum, the first three minerals are removed using a procedure that relies on corrosive sodium hydroxide, which is a highly basic compound.
Acid rain and acid precipitation differ?
acid precipitation is all kinds of precipitation like rain, dew and hail, while acid rain is only in the liquid form
-1
alkali metals: soft, highly reactive
Ions
charged particle from atoms that have gained/lost electrons. Many have complete outer orbits =stable -some in app. concentrations=necessary for health
-group
column of elements with similar properties
electrolyte
compound that separates into ions when dissolved in water (molecules pulled apart)=solution that conducts electricity
-potassium hydroxide
cosmetics, & soft/liquid soaps
Coefficients Vs. Subscripts
different amount of the same substance, subscripts change substance composition=different substance
-sodium hydroxide
drain cleaner
-atoms
electrically neutral, equal number of protons & electrons
-all atoms
electrically neutral, tot. number of electrons in orbits must = number of protons
-Anions
electrons>protons= - charge. +ide
General word equation: Other combustion reactions
element + oxygen-> oxide + energy
Products
end result chemicals (finishing materials) -ALWAYS on right side
Word equation
full chemical names, representing what has reacted and what has been produced -Proper names -NOT chemical formulas of all items
poly atomic ions
groups of atoms that stay -written, treated as one group/unit -Ionic charge is carried by whole group -same rule as binary -compound contains more than one of the polyatomic ion, put brackets around ion and use subscript for whole bracketed ion -several polys can be associated with each cation -indicate by placing brackets around polyatomic ion and writing subscript outside -EX. Mg(OH)2 -iron(III)nitrate= Fe (No3)3 -Na3PO4 -Do not change suffix -made of +1 atoms -charge spread all over entire ion -consider single unit (in chemical formula) for compound -compound has +1 poly atomic= curved brackets around ions subscript outside
-17
halogens: one of most reactive groups
Subscripts
how many atoms or ions there are within a compound/per molecule
Word Equation: Complete Combustion of Hydrocarbons
hydrocarbon + oxygen-> carbon dioxide + water + energy
Naming Rules: Oxyacids
identified as oxyacid, name non metal (in mid) but change to "ic acid" ending *no other additions needed
precipitate
in reaction of aqueous reactants, one product is an insoluble, solid -solid formed from reaction of two solutions -formed during reaction= appears as tiny solid specks in solution
molecule
individual. Particles bonded atoms, particle where atoms are joined by covalent bond
poly atomic ion
ion made of stable group of several atoms made up of one or more than one atom that acts as single particle -Sodium phosphate= sodium(cation) & phosphate (anion) -all ions=anions except ammonium -all anions end in "ate" except nitrite and hydroxide -same steps as ionic binary compounds -diff= anion named according to polyatomic not names of individual elements
SALT
ionic compound from water metal cation from base + nonmetal from acid
Naming Rules-Binary Ionic Compounds MONOVALENT
number of each ion must balance + & - charges so that overall charge=0 Electrons from metal to non metals Charged ions attract ooply charged ions until balanc=Neutral. Ion numbers must be simplest ratio No subscript "1" Super to subscript 2 elements w. charges & same sign will not bond
-Atomic number
number of protons in nucleus
Start balancing w....
omplicated, most different element compounds -Changing later=affect atom number of other already balanced elements
-arrangement
order of increasing atomic number
Products of neutralization
pH closer to 7 (neutral) than it was for either reactants -Potassium hydroxide (KOH) neutralized by cola (slightly acidic)
How
pollutants: sulfur dioxide (fossil fuels) & nitrogen oxides (vehicle engines) + water=acids before precipitating
Hydrocarbons Ex
powers cars, buses, warms houses, generates electricity, & candles
b. Acid precipitation is sometimes called "wet deposition". Why is this term appropriate?
precipitation is in a wet state technically speaking, it is in a liquid or wet state.
Chemical reaction
process where substances interact=new substances formation with new properties -During, reactant particles collide, allowing atoms or ions to rearrange & form products -absorb or release energy -if energy released>absorbed, word on right (with products) -if energy absorbed=on left (with reactants) -Chemical reactions always involve 1/+ reactants chaining to give 1/+ products
-Cations
protons>electrons= + charge
-Compounds
pure substance of 2 or + elements in fixed ratio
Combustion
rapid chemical reaction of substance where fuel "burns"/ reacts quickly with O2 -Products=oxide & energy -"Burning" -usually energy release= heat and sunlight
-VE ring
reactivity
pH scale
represents acidity or basicity of a solution, measure of how strong base/acid is -Scale ranges from 0-14 -Neutral solution (ie. pure water)=pH 7 -H & OH concentrations are equal -Healthy surface skin slightly acidic with pH 5.5 -Solutions highly basic or highly acidic =corrosive and reactive
-magnesium hydroxide
rolaids= 1 of active ingredients
-period
row of elements
Arrow
shows "process" where reactants converted to products
Balance coefficient on....
side with fewest of that atom type
-ionic bond
simultaneous strong attraction of + & - ions in ionic compound
Balancing Polyatomic ions
single unit as long as they are same on both sides
hydrogen
some properties in common with first column metals -lacks many characteristic physical properties of metals at room temp.
-full VE
stable
2 non metals bond, both nuclei
strong attraction for others electrons, no one wins "tug of wa" =share electrons bond
-chemical
substance description of what substance does as it forms 1 or + diff. substances
-physical
substance description that does not involve forming new substance -Ex. colour, texture, density, smell, solubility, taste, melting point & physical state
physical changes
substance remains same substance but changes physical properties in some way -EX. changes of state (melting, evaporation, condensation, sublimation, dissolving), many reversible
chemical changes
substances changes into 1 or + diff. substances -Products diff. from starting materials
+sign
use to separate +1 item -NOT WORD "PLUS -NO "="
#H atoms
value of charge of it related polyatomic ion -EX. phosphate ion, PO43-, has ionic charge of -3= H3PO4
main sources
vehicles and industrial and power generating plants
Which aquatic animals are most tolerant of acidic conditions?
water birds, other large organisms, Frogs Which animals are most affected by acidic conditions? fish, other small organisms snails
neutralization
where acid + base -products Always water & salt (ionic compound) -Subset of double displacement=any product from acid based reaction, not always tille -In general: acid + base=water + salt