Introduction
Have you ever tried baking a cake? If yes then you must be knowing that baking soda is one of the most essential materials required to get a fluffy cake. The commonly known baking soda is Chemically referred to as Sodium Bicarbonate with the molecular structure as NaHCO3. The baking soda is white-looking mostly found in the form of fine powder.
In this article, we shall be having a detailed discussion on the topic of Sodium Bicarbonate to give the students a complete understanding of the topic.
Table of Contents
Sodium Bicarbonate - An introduction
What is Sodium Bicarbonate
History of Sodium Bicarbonate
Production of Sodium Bicarbonate
Properties of Sodium Bicarbonate
Structure of Sodium Bicarbonate
Uses of Sodium Bicarbonate
Difference between baking soda and baking powder
Key learnings from the chapter
Frequently asked questions
What is Sodium Bicarbonate?
It is a chemical compound made up of carbon, sodium, oxygen and hydrogen.
It is a monosodium salt of carbonic acid.
It is a white crystalline odourless solid having a bitter taste.
The common name of sodium bicarbonate is baking soda/ cooking soda/ bread soda/ bicarbonate of soda. It is commonly used in the baking and pharmaceutical industries.
History
Sodium carbonate or soda ash was produced by French chemist Nicolas Leblanc in 1791. In the 1800s fishermen used sodium and potassium bicarbonates to preserve fish. Later in 1846 two American bakers Austin Church and John Dwight made baking soda from sodium carbonate and carbon dioxide in their factory for the first time.
Occurrence
Nahcolite is the mineral in which sodium hydrogen carbonate occurs naturally. It is the natural source of the compound and it is also found in many mineral springs.
Production of Sodium Bicarbonate
On a large scale it can be produced by reacting cold and concentrated solutions of brine (sodium chloride) with ammonia and carbon dioxide. This is the Solvay process used to manufacture sodium carbonate (washing soda).
The reaction can be written as under:
\[ NaCl + H_{2}O + CO_{2} + NH_{3} \rightarrow NH_{4}Cl + NaHCO_{3} \]
Sodium hydrogen carbonate is an intermediate product of this process. On heating at 373K, it decomposes to release carbon dioxide gas and forms sodium carbonate.
\[ 2NaHCO_{3} \rightarrow Na_{2}CO_{3} + H_{2}O + CO_{2} \]
Properties of Sodium Bicarbonate
It is weakly basic in nature. A solution of sodium bicarbonate is mildly alkaline because of the hydrolysis of sodium bicarbonate.
\[ NaHCO_{3} + H_{2}O → H_{2}CO_{3} + NaOH \]
\[H_{2}CO_{3} →H_{2}O + CO_{2}\]
The pH of a solution of sodium bicarbonate is 8.3.
With phenolphthalein it shows no colour change and methyl orange gives yellow colour.
It is sparingly soluble in water.
Its boiling point is 8510C and its melting point is 500C.
The molar mass or molecular weight is 84.0066 g/ mol.
On heating, it decomposes to release carbon dioxide gas and forms sodium carbonate.
\[2NaHCO_{3} \rightarrow Na_{2}CO_{3} + H_{2}O + CO_{2}\]
This reaction occurs when baking soda is heated during the cooking process. It is used in making baking powder and in effervescent drinks.
Structure of Sodium Bicarbonate
Sodium bicarbonate can be chemically written as NaHCO3.
It consists of a sodium cation (Na+) and bicarbonate anion (HCO3-).
It has a monoclinic lattice structure.
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It consists of one sodium atom, one carbon atom, one hydrogen atom and three oxygen atoms.
Uses of Sodium Bicarbonate
Baking soda is a versatile compound. It is quite cheap and because of its usefulness, it has become a common household substance. Its varied uses are:
In Medicine-
As an antacid- It is used to treat indigestion and heartburn. Its quick action provides temporary relief by reducing stomach acid. Its alkaline nature neutralizes the excess hydrochloric acid present in the stomach and relieves indigestion.
5% sodium bicarbonate infusion injection is given during medical emergencies such as serious renal failure, heart stroke, uncontrolled diabetes etc.
It is used in making beauty care products, cosmetics and personal hygiene products.
It is used in making ear drops.
It is used intravenously to reduce chemotherapy symptoms.
It is used in cleaning the mouth and teeth because of its antibacterial properties.
At Home-
It is a wonder chemical in the house used primarily as a cleansing agent, cooking ingredient and disinfectant. Its various uses are:
As a baking soda it is used to raise the batter of flour. Baking soda is used in making baking powder which is a mixture of baking soda and a mild acid such as tartaric acid. This baking powder is used as a leavening agent (a chemical used in batter and dough that releases gas and makes dough rise and expand) in baking bread, cakes, cookies, pancakes, patties etc.
When baking powder mixes with water present in cake dough, then sodium bicarbonate reacts with tartaric acid to produce carbon dioxide gas:
NaHCO3 + H+ (from tartaric acid)→ CO2 + H2O + Sodium tartrate. The carbon dioxide gas produced helps the cakes and breads to ‘rise’ and become soft and spongy. In the absence of baking powder, the cake turns out hard and small in size.
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Differences Between Baking Soda and Baking Powder
Baking soda is often added for faster cooking of food like gram or chana.
It is used in making aerated soda water and fizzy drinks.
Baking soda is used in soda acid type fire extinguishers. This extinguisher contains sodium hydrogen carbonate solution and sulphuric acid in two separate containers inside them. When the knob of the extinguisher is pressed the acid mixes with the soda solution to produce a lot of carbon dioxide gas. The CO2 gas comes out along with the streaming liquid. It falls on the burning substance and blankets out the supply of air thereby extinguishing the fire.
The liquid that falls on the burning substance also cools it and helps in bringing the ignition temperature down thereby putting off the fire.
It is used as a cleansing agent to clean floors, washbasin, kitchen utensils etc.
Baking soda is used as a disinfectant to kill bacteria from surfaces.
It is used as pest control to kill cockroaches and other pests.
It can be used to neutralize the effects of corrosion.
It can be used as a deodorizer to freshen up old carpets, rugs, cupboards, shoes, refrigerators and vaccum cleaners.
It can remove tough stains from the floor, clothes and furniture.
It is used in washing clothes to remove dirt and as a water conditioner/ softener.
In the Garden-
Baking soda can be used in the garden as a natural pesticide to kill harmful pests and fungus that attacks plants.
It can be added to soil to increase its pH level so that the soil becomes alkaline. Some plants prefer alkaline soils.
It can also be used to clean garden tools.
Health Hazard
Concentrated sodium bicarbonate solution causes severe irritation to the eyes and skin. In normal conditions, it is not toxic and dangerous. Overdose of sodium bicarbonate may result in shortness of breath, muscle spasm, mood changes, jerks and fits. Precaution must be taken in administering sodium bicarbonate to patients suffering from kidney failure, high blood pressure, heart failure and kidney stones.
Key points from the chapter -
Sodium Bicarbonate is the chemical compound of carbon, sodium, oxygen, and hydrogen
Sodium Bicarbonate is alkaline in nature with pH level of around 8 and increases the pH level of other materials when added in them
Activation can happen by adding acid or heating at more than 500C
It has multiple applications like medicine, at home, for cooking and baking, etc.
Precautions need to be taken while consuming it and avoiding consumption in large quantities.
Thus we see that baking soda is a very important compound of sodium and it occupies a special place in our homes and lives. Take up questions related to the topic to evaluate your understanding of the topic.
FAQs on Sodium Bicarbonate - NaHCO3
1. Is sodium bicarbonate harmful to human health?
Generally, sodium bicarbonate is not considered harmful to human health. However, if the quantity of its consumption increases widely it may cause certain challenges like Gastrointestinal irritation, Stomach heaviness, loss of appetite, vomiting, etc, and also inhalation may cause coughing and sneezing. Thus, doctors recommend patients, especially those with kidney disease and pregnant women to avoid the consumption of sodium bicarbonate or baking soda.
2. How does sodium bicarbonate affect the pH level?
Sodium bicarbonate is naturally alkaline with a pH level of 8. So, when it is added to a swimming pool it increases the alkalinity and the pH level of the pool, making it more stable and clearer.
The human body also raises the pH level of the blood. Sodium bicarbonate is the monosodium salt of carbonic acid. It forms sodium and bicarbonate ions. The ion so formed increases plasma bicarbonate and buffers excess hydrogen ion concentration. Thus, increased the pH level.
It can be added to the soil to increase the pH level of the soil.
3. At what temperature does sodium bicarbonate start melting?
Sodium bicarbonate which is chemically represented as NaHCO3, starts melting when heated above about 800C. As the substance starts getting heated it breaks down into sodium carbonate, water, and carbon dioxide. This process of disintegration is called thermal decomposition where heat decomposes the molecular structure of baking soda.
4. How does sodium bicarbonate get activated?
Sodium bicarbonate can be activated using different methods like -
Mixing Sodium bicarbonate with an acid activates it
Or pairing the baking soda with other agents like lemon, buttermilk, yoghurt, or brown sugar
Even without adding any acid, it can be activated when heated at a temperature of more than 122°F, which make the cake you bake fluffy
Basically, when it gets activated it gives off carbon dioxide to the mixture which causes the mixture to expand. And as the mixture is cooked the carbon dioxide present gets replaced by the air leaving the cake to be lighter.
5. Is there a difference between baking soda and baking powder?
There is a basic difference between the two, as a Baking soda is Sodium bicarbonate and needs acid to activate it, while baking powder has both Sodium bicarbonate and acid. Thus, it requires only water to activate the chemical. Also, baking soda is three to four times stronger than baking powder. However, both can work irreplaceably with careful adjustments and precautions.
