Monday, 29 June 2015

Understanding Acids and Alkalinity

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


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


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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