Tag: substances in common use

Sodium Bicarbonate (NaHCO3) is called baking soda because when heated, it releases carbon dioxide gas, which is responsible for the rising of cookies, doughnuts, and bread.

Sodium bicarbonate, also commonly known as baking soda, is commonly seen as a white, fine powder and has the chemical formula NaHCO₃. It has one sodium atom, one hydrogen atom, one carbon atom, and three oxygen atoms. It is a very useful chemical that is alkaline in nature.

Sodium bicarbonate 

Baking soda is the common name of Sodium bicarbonate

The reaction between baking soda (sodium bicarbonate) and vinegar (dilute acetic acid) generates carbon dioxide gas and sodium acetate.
$ NaHCO _3 + CH _3COOH \rightarrow  CH _3COONa + H _2O + CO _2 $

A constituent of gasoline is octane $\displaystyle C _8H _{18}$.
Gasoline is also known as petrol. it contains a mixture of hydrocarbons.

The production of carbon dioxide is main characteristic of baking soda that makes it suitable for baking.Baking soda gives carbon dioxide and water vapour on heating at even low temperature such as $1000^oC$. The gas so formed turns lime water milky, which confirms the presence of carbon dioxide gas. When Washing soda ($Na _2CO _3$) is heated it does not produce carbon dioxide even at high temperature, such as $200^0C$ or $300^oC$. However sodium carbonate gives sodium oxide and carbon dioxide when heated at about $1000^oC$.

The gas produced by heating of the samples can be checked by passing through lime water. If the lime water turns milky then the evolved gas is carbon dioxide and the heated substance is baking powder.

$2NaHCO _{3} \xrightarrow{Heat} Na _{2}CO _{3} + H _{2}O + CO _{2}$

$Na _{2}CO _{3}.10H _{2}O \xrightarrow{Heat}Na _{2}CO _{3} + 10H _{2}O$

From the above reaction, it shows that washing soda ($Na _2CO _3$) on heating gives sodium oxide and carbon dioxide.

 Sodium hydrogen carbonate or sodium bicarbonate is used as a fire extinguisher. When heated to a high temperature, the chemical properties of this salt make it produce lots of carbon dioxide and remove oxygen. This reduces the amount of oxygen and puts the fire out. The reaction also produces a small quantity of water and sodium carbonate as by-products.
$2NaHCO _3 + H _2SO _4 \rightarrow Na _2SO _4 + 2H _2O + 2CO _2$

Solution of sodium hydrogen carbonate is mildly alkaline due to the formation of carbonic acid and hydroxide ion:
$ HCO _3 + H _2O \rightarrow H2CO _3 + OH-$