Don't Play Mad Scientist
Just remember that anytime
two chemicals with completely different formulas and / or functions are
combined, at best the effectiveness of each chemical is reduced, and/or the
chemicals may not be compatible
Don't haphazardly mix
chemicals; pay attention to the order in which chemicals are to be added to
each other and do not deviate from the instructions. Even chemicals that mix to
produce seemingly safe products should be handled carefully.
For example,
hydrochloric acid and sodium hydroxide will give you salt water, but the
reaction could break your glassware or splash the reactants onto you if you
aren't careful. Some rules are NOT made to be broken. That is true of the rules
used for chemicals. They are established for your safety and those of other’s
What is the difference between an acid and an alkali?
The strength of the acidity
or alkalinity is expressed by the pH
scale. An acid usually has a chemical formula with H at the beginning
of, its strength depends on its concentration of the hydronium ions. A base (Alkali)
has a chemical formula with OH at the end of it, its strength depends on concentration of the hydroxide
ions
An acid (often represented
by the generic formula HA) is traditionally considered any chemical compound
that when dissolved in water yields
hydronium ions as the only positive charged ions and gives a solution
with a pH of less than 7. That approximates the modern definition of Brønsted
and Lowry, who defined an acid as a compound which donates a hydrogen ion (H+)
to another compound (called a base). Common examples include acetic acid (in
vinegar) and sulfuric acid (used in car batteries). Acids generally taste sour
In chemistry, an alkali is a
compound which when dissolved in water yields hydroxyl ions as only negative
charged ions, an alkali is a specific type of base, formed as a carbonate,
hydroxide or other basic (pH greater than 7) ionic salt of an alkali metal or
alkali earth metal element. The word alkali or the adjective alkaline are
frequently used to refer to all bases, since most common bases are alkalis,
although strictly speaking this is inaccurate.
Types
of Acids and Bases (Alkali)
Acids can be
classified as Mineral acids, Sulfonic acids, Carboxylic acids, Vinylogous
carboxylic acids and Nucleic acids. Some common acids include Hydrochloric acid
(HCl), Sulphuric acid (H2SO4), Nitric Acid (HNO3),
Acetic acid, Citric acid and Lactic acid amongst several others.
Bases are of 2
types – a base and an alkali (a soluble base). Some common bases include
Potassium Hydroxide (KOH), Sodium Hydroxide (NaOH) and Magnesium Hydroxide (Mg
(OH) 2).
pH measurement
The term pH is a measurement
of the relationship between hydrogen ions and hydroxyl ions. When you have more hydrogen ions than
hydroxyl ions, you have an acid.
Likewise, if you have more hydroxyl ions than hydrogen ions you have a
base (alkali).
The pH scale is a
measure of the acidity or basicity (Alkali) of a solution. It is approximates
but is not equal to p [H], the negative logarithm base 10) Base (Acid) 1-7,
Alkaline 7- 14; the pH of a solution is temperature-dependent.
Unfortunately
the pH scale is logarithmic; for every integer that the scale decreases the
material is 10 times more acidic. Those of us in earthquake country know all
too well the consequences of a change of from 6 to 7 on the logarithmic,
Richter scale. The difference in the pH scale is just as dramatic and therefore
just as misleading.
Be
cognizant that an acid or high alkaline product should
not be allowed to dry on the surface since their aggressiveness continuously
increases as the water is evaporated. Also, as they are heated (reactivity)
they become more aggressive.
Base (Alkali)
Alkalis neutralize acids, and solutions of
alkali are greasy to the touch. The strength of an alkali is measured by its
hydrogen-ion concentration, indicated by the pH value.
They may be divided into strong and weak
alkali: a strong alkali (for example, potassium hydroxide, KOH) ionizes
completely when dissolved in water, whereas a weak alkali (for example,
ammonium hydroxide, NH4OH) exists in a partially ionized state in solution. All
alkalis have a pH above 7.0.
The hydroxides of metals are alkalis. Those of
sodium and potassium are corrosive; both were historically derived from the
ashes of plants.
The four main alkali are-
1.
Sodium hydroxide (caustic soda, NaOH)
2.
Potassium hydroxide (caustic
potash, KOH)
3.
Hydroxide calcium (slaked lime or limewater, Ca (OH) 2)
4.
Aqueous ammonia (NH3 (aq)). Their
solutions all contain the hydroxide ion OH-, which gives them a characteristic
set of properties.
Strength of an Acid in Solution
Acid [: (from the Latin acidus meaning sour) is a chemical
substance whose aqueous solutions are characterized by a sour taste, the
ability to turn blue litmus red, and the ability to react with bases and
certain metals (like calcium) to form salts. Aqueous solutions of acids have a
pH of less than 7]
An acid dissociation constant, Acidity (pKa) (also
known as acidity constant) is a quantitative measure of the strength of an acid
in solution.
·
Hydrofluoric acid - 3.17
·
Hydrogen peroxide - 11.7
·
Oxalic acid - 1.27
·
Hydrogen sulphate - 1.99
·
Citric acid - 3.128
·
Acetic acid - 4.756
Acid
Strong acids include
the heavier hydrophilic acids: however, Hydrofluoric Acid (HF) is relatively
weak. Acids are acids by virtue of the presence of an excess of hydrogen ions
in the solution, Their salts are created when the positive hydrogen ions are
replaced with positive metal ions, for example when Hydrochloric Acid (HCL) reacts
with Sodium (Na) to produce NaCl with the release of H2 gas.
1.
Hydrochloric Acid
(HCI): or Muriatic Acid, its historical but still occasionally used name, this
is a highly corrosive acid (pH of -1) and is often used to clean calcium
carbonate build up from the inside of kettles or from around water faucets and
from shower heads;
2.
Sulphuric Acid
(H2 SO4): this is a common acid in both the laboratory and industry. It is both
highly corrosive and economical to manufacture, which makes it the reagent of
choice for many applications;
3.
Phosphoric Acid
(H3PO4): this acid is used to remove rust and rust stains from metal tools and
from car bodies undergoing repairs;
4.
Nitric Acid
(HNO): this is another common laboratory acid used as a reagent in many
chemical tests and experiments due to the fact that almost all of its products
(salts) are soluble in water;
5.
Hydrofluoric Acid
(HF): This acid is extremely corrosive and has the unique property of being
able to etch (eat away) glass. Consequently it is used in industry to write
signs on glass windows in stores and office buildings or on glass products.
Acids, Bases, and pH
Water
quality and pH are often mentioned in the same sentence. The pH is a very
important factor, because certain chemical processes can only take place when
water has a certain pH. For instance, chlorine reactions only take place when
the pH has a value of between 6.5 and 8.
pH
literally means the weight of hydrogen. pH is an indication for the number of
hydrogen ions. It consisted when we discovered that water consists of hydrogen
ions (H+) and hydroxide ions (OH-). pH is an indication for the acidity of a
substance. It is determined by the number of free hydrogen ions (H+) in a
substance. The common term for pH is alkalinity.
Acidity
is one of the most important properties of water. Water is a solvent for nearly
all ions. The pH serves as an indicator that compares some of the most
water-soluble ions. The outcome of a pH-measurement is determined by a consideration
between the number of H+ ions and the number of hydroxide (OH-) ions. When the
number of H+ ions equals the number of OH- ions, the water is neutral. It will
than have a pH of about 7.
The
pH of water can vary between 0 and 14. When the pH of a substance is above 7,
it is a basic substance. When the pH
of a substance is below 7, it is an acid
substance. The further the pH lies above or below 7, the more basic or acid
a solution is.
The
pH is a logarithmic factor; when a solution becomes ten times more acidic, the
pH will fall by one unit. When a solution becomes a hundred times more acidic
the pH will fall by two units.
Total alkalinity
Is
frequently referred to as AT, defined as the amount of acid required
to lower the pH of the sample to the point where all of the bicarbonate [HCO3-]
and carbonate [CO3-] could be converted to carbonic acid [H2CO3]. This is
called the carbonic acid equivalence point or the carbonic acid endpoint.
When
an acid substance ends up in water, it will give up a hydrogen ion to the
water. The water will than become acid. The number of hydrogen ions that the
water will receive determines the pH. When a basic substance enters the water
it will take up hydrogen ions. This will lower the pH of the water. When a
substance is strongly acidic it will give up more H+ ions to the water. Strong
bases will give up more OH
There
are several ways to define acids and bases, but pH only refers to hydrogen ion
concentration and is only meaningful when applied to aqueous (water-based)
solutions. When water dissociates it yields a hydrogen ion and a hydroxide.
Pure
water is said to be neutral, with a pH close to 7.0 at 25 °C (77 °F). Solutions
with a pH less than 7 are said to be acidic and solutions with a pH greater
than 7 are said to be basic or alkaline.
The following is a generalized list of
examples of pH:
·
pH 0 battery acid
·
pH 1 hydrochloric acid
·
pH 2 lemon juice, vinegar
·
pH 3 grapefruit
·
pH 4 tomato juice
·
pH 5 black coffee
·
pH 6 urine/saliva – acidic ^
·
pH 7 fresh water, milk – Neutral
·
pH 8 sea water – base substances (alkali) v
·
pH 9 baking soda
·
pH 10 Milk of Magnesia®
·
pH 11 ammonia
·
pH 12 soap
·
pH 13 bleach
·
pH 14 liquid drain cleaner
Reactivity
Add
moisture (dew, rain, car washing etc.) and heat to this equation (reactivity) all
of which equates to a highly concentrated solution, which causes a concave
indentation (etching or alkaline staining) to the paint surface. This must be neutralized to stop the ongoing reaction
process as moisture acts as a catalyst and a carrier system, which will
permeate the paint system matrix.
Neutralization of
acids and bases
When
an alkali is added to an acid, the pH of the mixture rises as the alkali reacts with it, forming neutral
products. An acid added to an alkali causes the pH to fall because the alkali
is removed by reaction with the acid. A reaction in which acidity or alkalinity
is removed is called neutralisation.
A neutralisation involving an acid and a base (or alkali) always produces salt
and water (and nothing else).
If
the affected paintwork is not neutralized any remaining acid residue will be
reactivated each time it comes into contact with moisture and heat. Water
contains 2- hydrogen and 1-oxygen atom and will acts as a catalyst and a
carrier system for acid. Oxygen is an oxidizer; ozone is an allotropic form of
oxygen (an oxidizer is any component that emits oxygen); many chemical
compounds react to slight heating and an oxidizing process.
Sodium
bicarbonate or sodium hydrogen carbonate is the chemical compound with the
formula NaHCO3Many laboratories keep a bottle of sodium bicarbonate powder
within easy reach, because sodium bicarbonate is amphoteric, reacting with
acids and bases. Furthermore, as it is relatively innocuous in most situations,
there is no harm in using excess sodium bicarbonate
Surface
preparation - wash and then clean the paint surface by using a chemical
paint cleaner (Klasse all in one (AIO) or ValuGuard "N" New Car Prep
Acid - ValuGuard Acid
Neutralizer (Step I) - diluted 1:8 with distilled water it neutralizes acids
deposited on the paint surface and in the micro-pores of the paint
Base (Alkalis)
- ValuGuard
Alkaline Neutralizer (Step II) - deep-cleans painted surfaces to remove
alkaline deposits
Acid
/ Alkali Etching Removal –
1.
First clean the paint surface and then
neutralize the acid or alkali
2.
Use a
machine polish (Optimum Polish, Optimum
Compound) and a cutting (LC White,
Orange or Yellow) foam pad (speed # 4- 5.0 or 1200 RPM) to level the surface
3.
For PPG
CeramiClear™ Clear Coat or other hard clear coats substitute Menzerna for
machine polish; i.e. PO 203 S - Power Finish
4.
Use the
least aggressive polish/foam pad first, if this doesn’t remove the problem
step-up to a more aggressive polish / foam pad set-up
5.
If none of
the above remove the etching use a wet-sanding process with 2000, 2500 and
then 3000 (or 4000) grit finishing paper
I would like to
think that these articles become an asset to anyone who is new to detailing and
to professionals alike, as well as industry experts who seek to advance their
knowledge.
I hope the
above article was informative. By having some understanding of the ‘What’ and
‘Why’ as well as the ‘How’ along with a little science to help you understand
how the chemicals we use react, you can achieve the results you desire.
I would appreciate it if you
would share this article as it helps other detailers further their knowledge.
Questions and/ or constructive comments are always appreciated.
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