Sodium Carbonate : Properties, Preparation and Uses
Sodium carbonate have formula Na2CO3. From all metals group elements, only alkali metal form soluble carbonate in water and sodium carbonate is most important of alkali metal carbonate.
Sodium carbonate is exists in three form, that is:
Usually, when we heat the hydrate crystal of any substance, all water molecules that trap in the crystal will lose. But it is not happened in the decahydrate crystal of sodium carbonate. When we heat this crystal, they form a powdery deposit of monohydrate.
Na2CO3.10H2O(s) → Na2CO3.H2O(s) + 9 H2O(g)
Preparation Of Sodium Carbonate
Sodium carbonat has many important role in chemistry. So, because of that, it produced in large quantities every years .
Long time ago, we produced sodium carbonate with process called Solvay or ammonia – soda process. But, there are a reaction in this process that produce a substance that cause many environmental problem. So now, it is preferable to mine underground deposits to get sodium carbonate.
The largest quantity of sodium carbonate deposit in the world is found in Wyoming with amount about 4,5 x 1010 tonnes.
Deposit of sodium carbonate called trona , which is contain about 90 percent of mixed carbonate – hydrogen carbonate, with formula Na2CO3.NaHCO3.2H2O. This substance also called sodium sesquicarbonate. Sodium sesquicarbonate is not a mixture of two compound, but it is a single compound with actual formula Na2(HCO3)(CO3).2H2O.
Trona is mined about 400 m underground, crushed and then heated in rotary kilns. This process change sodium sesquicarbonate to carbonat.
2 [Na2CO3.NaHCO3.2H2O (s)] → 3 Na2CO3(s) + 5 H2O(g) + CO2(g)
An then, the sodium carbonate that produced is dissolved in water. As we mention before, the sodium carbonate is soluble in water so the insoluble impurities will be set down and then filtered of.
The next step is evaporating the sodium carbonate solution to dryness producing sodium carbonate monohydrate. By heating sodium carbonate monohydrate in rotary kilns gives the anhydrous of sodium carbonate :
Na2CO3.H2O(s) → Na2CO3(s) + H2O(g)
Even though the Solvay process is not recommended as a process to produce sodium carbonate, many country still using it. In fact, about 70 percent of the world’s supply of this substance is produced by Solvay process.
Uses of Sodium Carbonate
Sodium carbonate is used in glass manufacture. Sodium carbonate is reacted with silicon dioxide and other components at about 1500 degC. This process will produced sodium silicate that used to make glass.
Na2CO3(l) + x SiO2(s) → Na2O. x SiO2(l) + CO2
Sodium carbonate is also used to remove alkaline earth metal ions from water supplies. In the process, if in the water exist alkaline earth metal ion, they going to be react with sodium carbonate to form insoluble alkaline earth metal carbonate. This insoluble substance will be settled down and then filtered of.
The alkaline earth metal ions that really need to remove is calcium and magnesium. High concentration of this ions in water will make our soap cannot produce much bubbles. They also can produce precipitate when heating the water.
- Anhydrous state with formula Na2CO3. This form also known as soda ash
- Monohydrate with formula Na2CO3.H2O
- Decahydrate with formula Na2CO3.8H2O. This is the commonly form that also know as washing soda.
Usually, when we heat the hydrate crystal of any substance, all water molecules that trap in the crystal will lose. But it is not happened in the decahydrate crystal of sodium carbonate. When we heat this crystal, they form a powdery deposit of monohydrate.
Na2CO3.10H2O(s) → Na2CO3.H2O(s) + 9 H2O(g)
Preparation Of Sodium Carbonate
Sodium carbonat has many important role in chemistry. So, because of that, it produced in large quantities every years .
Long time ago, we produced sodium carbonate with process called Solvay or ammonia – soda process. But, there are a reaction in this process that produce a substance that cause many environmental problem. So now, it is preferable to mine underground deposits to get sodium carbonate.
The largest quantity of sodium carbonate deposit in the world is found in Wyoming with amount about 4,5 x 1010 tonnes.
Deposit of sodium carbonate called trona , which is contain about 90 percent of mixed carbonate – hydrogen carbonate, with formula Na2CO3.NaHCO3.2H2O. This substance also called sodium sesquicarbonate. Sodium sesquicarbonate is not a mixture of two compound, but it is a single compound with actual formula Na2(HCO3)(CO3).2H2O.
Trona is mined about 400 m underground, crushed and then heated in rotary kilns. This process change sodium sesquicarbonate to carbonat.
2 [Na2CO3.NaHCO3.2H2O (s)] → 3 Na2CO3(s) + 5 H2O(g) + CO2(g)
An then, the sodium carbonate that produced is dissolved in water. As we mention before, the sodium carbonate is soluble in water so the insoluble impurities will be set down and then filtered of.
The next step is evaporating the sodium carbonate solution to dryness producing sodium carbonate monohydrate. By heating sodium carbonate monohydrate in rotary kilns gives the anhydrous of sodium carbonate :
Na2CO3.H2O(s) → Na2CO3(s) + H2O(g)
Even though the Solvay process is not recommended as a process to produce sodium carbonate, many country still using it. In fact, about 70 percent of the world’s supply of this substance is produced by Solvay process.
Uses of Sodium Carbonate
Sodium carbonate is used in glass manufacture. Sodium carbonate is reacted with silicon dioxide and other components at about 1500 degC. This process will produced sodium silicate that used to make glass.
Na2CO3(l) + x SiO2(s) → Na2O. x SiO2(l) + CO2
Sodium carbonate is also used to remove alkaline earth metal ions from water supplies. In the process, if in the water exist alkaline earth metal ion, they going to be react with sodium carbonate to form insoluble alkaline earth metal carbonate. This insoluble substance will be settled down and then filtered of.
The alkaline earth metal ions that really need to remove is calcium and magnesium. High concentration of this ions in water will make our soap cannot produce much bubbles. They also can produce precipitate when heating the water.
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