Decomposition of Carbonic Acid Culminating by Elizabeth Burke

Carbonic Acid = Carbon Dioxide + Water

H2CO3

Visual Representation of Balanced Chemical Equation:

Balanced Chemical Equation: H2CO3 = CO2 + H2O

H2CO3 is in equilibrium with CO2 + H2O

Physical and Chemical Properties of the Reactant: the reactant is not stable and cant be isolated. It only exists as a solution in water. Carbonic acid is a weak acid.

How the Reactant is Obtained: one of the ways the carbonic acid is formed is by dissolving carbon dioxide in water. You can dissolve more of the carbon dioxide in if there is higher pressure exerted on the gas. It could also be obtained by reacting bicarbonate or carbonate with an acid. For example, when baking soda (sodium  bicarbonate) is mixed with vinegar (acetic acid), carbonic acid is formed and immediately begins to decompose giving off carbon dioxide.

Conditions for reaction to occur? the reaction occurs only when the reactants are put in water. What can help the reaction happen faster is high temperature or being in an acidic solution (pH <7). The reaction is slower when it is in a basic solution (pH >7) or when the pressure is increased.

Type of Reaction: decomposition. This reaction is decomposition because the carbonic acid is breaking down into carbon dioxide and water.

Physical and Chemical Properties of the Products: carbon dioxide (CO2) is a colorless gas. It’s melting point is -78 °C and the boiling point is -58 °C. Water (H2O) is colourless and odorless. It’s melting point is 0 °C and it’s boiling point is 100 °C.

Uses for Products of Reaction: the products of this reaction are quite common, but carbon dioxide gathered from the decomposition of carbonic acid is important in the food industry as a leavening agent and in carbonated drinks.

Significance of Reaction to Industry:

– used in soft drinks to make them carbonated: the decomposition of carbonic acid is responsible for the in carbonated beverages such as soft drinks, beer, champagne and carbonated water.

– used in baked goods to make them rise: baking powder is a mixture of sodium bicarbonate and an acid and when they are dry they do not react together, but when they are dissolved together, carbonic acid starts to decompose releasing carbon dioxide which makes the dough or batter rise.

History: carbonic acid has been around since carbon dioxide existed on earth and since carbon dioxide is in the atmosphere, carbonic acid is found anywhere water is. It plays an important role in managing the pH of water. One of the salts of carbonic acid (calcium carbonate) are also found in the earths crust and the shells and skeletons of animals. Another one of the salts (sodium carbonate) is used in the making of glass.

References:

http://en.wikipedia.org/wiki/Carbonic_acid

Busch, D. H., Shull, H., Conley, R. T., (1978) Chemistry.  Boston: Allyn and Bacon Inc.

http://en.wikipedia.org/wiki/Water

http://en.wikipedia.org/wiki/Carbon_dioxide

 

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