Acids and Bases


Acids and bases are a common part of everyday life and depending on the strength of the acid or base can be quite dangerous. The simple hydrogen ion or proton (H+) plays an important role in several chemical and all biological systems. Acids and bases is a topic with lots of real world examples, which makes it an interesting and relevant topic.


Online Resources               Home    Chemistry    Top               Previous    Next


  • Acid-Base Solutions – PhET – interactive on acids and bases where students can change various conditions and observe the effect on the composition of acid and base molecules in the solution. There are two tabs. In the “Introduction” tab, students can choose from 5 solutions (water, strong acid, weak acid, strong base, weak base) and perform 3 tests (pH meter, pH paper and conductivity). In the “Custom Solution” tab, the same tests can be performed but students can adjust the concentration and strength of the solution to see how it affects the solution
  • Acid Lake – Teacher’s Domain – animated slideshow that looks at the effect of acid rain on a lake. Each slide reduces the pH level in the lake and explains the effects on plants and animals in the ecosystem. Contains a brief introduction to the pH scale
  • Virtual Lab – The Chemistry Collective – online lab where students can mix several acids and bases to see the effects on pH and the concentration of each species
  • Water – Cell Biology Animation – animated slideshow that takes an in-depth look at the structure of water, the interaction between different water molecules (including the structure of ice), the hydronium and hydroxyl ions, an introduction to acids, the concentration of H+ ions [H+] in a solution and the relationship between [H+] and pH. The slideshow finishes with a pH slider that shows the concentration of H+ ions and common household items


Real World               Home    Chemistry    Top               Previous    Next


    • acid rain – the combustion of fossil fuels at coal power plants, factories and motor vehicles releases sulfur dioxide and nitrogen oxides (pollution) into the atmosphere. These gases react with water and produce acid. Acid rain affects waterways, aquatic life, soils, forests and damages buildings and statues

  • ammonia – NH3 – ammonium hydroxide (NH4OH) is used in cleaning products
  • ant bites – formic acid – HCOOH
  • baking soda – sodium bicarbonate or sodium hydrogen carbonate – NaHCO3 – used in baking – when mixed with other acids in the food it release CO2, which makes the food rise, e.g. bread, cakes
  • battery acid – sulfuric acid – H2SO4
  • bleach – used in cleaning – hydrogen peroxide – H2O2
  • blood – pH = 7.4 – the pH of blood is influenced mainly by the reaction of carbon dioxide (CO2) with water (H2O) to form carbonic acid (H2CO3), which breaks down into the bicarbonate ion (HCO3-) and the hydrogen ion (H+)
  • cheese – rennet (a complex of enzymes isolated from stomach acid) is added to milk, which acidifies and curdles the proteins in the milk. The curds are collected to make cheese
  • corrosive placard – part of the Australian Dangerous Goods (ADG) code. All transport that carries large volumes of corrosive materials are required to display the placard on the vehicle
  • digestive system
    • mouth – pH = 6.8 – bacteria produce plaque acids
    • stomach – pH = 2.0
    • small intestine – pH = 7.6
  • jellyfish sting – Box Jellyfish – recommended on-the-spot treatment is vinegar, which disables the nematocysts the jellyfish fires into the skin, until an antivenom can be administered
  • lactic acid – produced in muscles during strenuous exercise – when the body needs a quick source of energy (ATP), the energy stored in the chemical bonds of glucose is broken down without using oxygen (anaerobic respiration) in a process called glycolysis. Glycolysis produces 2 molecules of ATP per 1 molecule of glucose, which are used to power muscle contraction. The end product in glycolysis is pyruvate. Pyruvate is normally transported into the mitochondria to be broken down further using oxygen (aerobic respiration). This produces an additional 36 ATP molecules. However, this process is too slow when the body needs energy quickly. Pyruvate starts to build up in the cytosol and inhibits the breakdown of further glucose by negative feedback inhibition of the enzymes in glycolysis. What the cells do is convert the excess pyruvate into lactic acid. This reduces the amount of pyruvate in the cell, which prevents negative feedback inhibition and allows the cell to continue to breakdown glucose and produce ATP quickly.
  • oranges, lemons and limes – citric acid – C6H8O7. Citric acid is the first molecule in the citric acid cycle (also called the Kreb's cycle or TCA (tricarboxylic acid) cycle). The citric acid cycle is the second stage (after glycolysis and before the electron transport chain) in the aerobic breakdown of glucose to produce ATP. It occurs in the mitochondria and produces 3 NADH, 1 FADH2 and 1 GTP (equivalent to ATP) per cycle. NADH and FADH2 feed into the electron transport chain to produce 3 ATP and 2 ATP per molecule respectively.
  • sherbet – an effervescent sweet powder that bubbles when eaten. Saliva in the mouth provides the water allowing the chemical reaction to occur. CO2 bubbles are produced when the edible acid (citric acid, malic acid or tartaric acid) and edible base (sodium bicarbonate, sodium carbonate or magnesium carbonate) react in the presence of water (saliva) to produce carbon dioxide and a chemical salt. Flavouring is added to make the sherbet taste sweet but this flavouring plays no role in the chemical reaction.
  • soft drinks – carbonic acid – H2CO3 – carbon dioxide gas is forced into solution under high pressure and reaction of the carbon dioxide (CO2) with water (H2O) produces carbonic acid (H2CO3). Carbonic acid dissociates in solution to form bicarbonate ions (HCO3-) and hydrogen ions (H+). The same process occurs in our bloodstream when carbon dioxide is released from cells as a biproduct of cellular respiration, except that the concentration of carbon dioxide is much lower and the pH in the blood is tightly regulated.
  • stomach acid – hydrochloric acid – HCl
  • swimming pool – hypochlorous acid – HOCl
  • tooth whitening – bleach – hydrogen peroxide (H2O2 ) or carbamide peroxide (CH6N2O3)
  • toothpaste – contains several basic compounds that neutralize plaque acids produced by bacteria in the mouth and act as abrasives – most cleaning of the teeth comes from the physical action of brushing teeth, rather than chemical action
  • vinegar – acetic acid
  • vitamin C – ascorbic acid – H2C6H6O6
  • White King – cleaning product
    • sodium hydroxide – NaOH
    • sodium hypochlorite – NaOCl


Key Knowledge               Home    Chemistry    Top               Previous    Next


  • acid – a chemical that donates H+
  • base – a chemical that receives H+
  • pH – a measure of the concentration of H+ ions in a solution
  • pH scale – pH 0 to 14
  • strong acids/bases and weak acids/bases
    • strong acids – acids with a low pH
    • weak acids – acids with a high pH
    • neutral – substances with a pH of 7.0
    • weak bases – bases with a low pH
    • strong bases – bases with a high pH
  • pH calculations
    • pH is a logarithmic scale – this means that an increase in 1 pH unit is a 10 times increase in the H+ concentration, e.g. pH 4.2 contains 10 times the amount of H+ than pH 3.2
    • pH = -log10[H+]
    • [H+] = 10-pH
  • corrosive – placard
  • pH indicator – a chemical that changes colour in solution depending on the concentration of H+ ions
  • buffer – a solution that resists changes in pH
  • neutralization – acid + base --> salt + water
  • MASH – metal + acid --> salt + hydrogen


Topic Ideas               Home    Chemistry    Top               Previous    Next


  • cheese making – students can make ricotta cheese by mixing vinegar with milk 


Images               Home    Chemistry    Top               Previous    Next


  • Seen an amazing image? Let me know! Contact me here. Please remember that I need permission to use images on this website. So if you can provide a link to the original image or even the credits (author, title, URL) and confirmation that I have permission to use the image that would be great.


#101 Tia 2015-04-20 07:27
Hi, i read your blog occasionally and i own a similar one and i was
just curious if you get a lot of spam responses?

If so how do you stop it, any plugin or anything you can suggest?
I get so much lately it's driving me insane so any assistance is very much appreciated.

Also visit my webpage; sydney attractions pass:

Add comment

Security code