[Chemistry Class Notes] on Sodium Bisulfate Pdf for Exam

Bisulfate salts are basically the salt of the anion HSO4^–. Sodium bisulphate is the most popular bisulphate compound. This bisulphate is formed by the sodium cation and HSO4^– anion. This salt is formed by the partial neutralization of sulphuric acid by the equivalent amount of sulphuric base. This base can be either in the form of sodium hydroxide or sodium chloride most probably. Anhydrous form of sodium bisulphate is hygroscopic. Solutions of Sodium bisulfate are mostly acidic with (1 M) molarity solution of sodium sulphate having pH approximately equal to 1.

 If we talk about its properties in brief then the sodium bisulphate monohydrate has a melting point of approximately 183° C. Talking about its Cass number, then the Cass number of sodium bisulphate is 10034-88-5.

Sodium bisulphate in small amounts does not harm but if it is consumed in large amounts in the body, it can be very harmful. Sodium bisulphate is actually a dry acid.

Talking about sodium bisulfite or sodium hydrogen sulphate.

Sodium Hydrogen Sulphate (NaHSO₄) is also known as Sodium Bisulfate. It is the sodium salt (NaCl) of the bisulphate anion [ SO_{4}^{2-}].

Sodium Bisulfate is an acidic salt (acidic solution is produced after salt is dissolved in a solvent)which is produced by partial neutralization of Sulfuric acid (H2SO4)with an equivalent amount of sodium base, basically in the form of sodium hydroxide (NaOH) or sodium chloride (NaCl). The anhydrous is being hygroscopic in nature. The solutions of Sodium Bisulfate are acidic in nature with a pH value of 1 for every 1M solution. It is a white and relatively dry granulated compound. It is corrosive to metals and tissues and also is soluble in water.

What is the Structure and Type of Bonding in Sodium Bisulfate?

The structure of Sodium Bisulfate molecules is explained in the figure below. It is observed that this compound features an ionic bond (overall transfer of valence electron/electrons between atoms) amongst the negatively charged bisulphate anion (HSO4^–) and the positively charged sodium cation (Na⁺). It has a Sulphur atom bonded with one hydroxyl group (OH^– or HO^–) and three oxygen atoms.

The accurate mass and the monoisotopic mass of Sodium Bisulfate (NaHSO₄) is 119.9 g/mol. The number of hydrogen bond donors is equal to one and the number of hydrogen bond acceptors equals four.

What Are The Properties of Sodium Bisulfate?

Physical Properties: Sodium Bisulfate of NaHSO4 is usually accessible in both monohydrates (hydrates consisting of one mole of water/mole of the compound), NaHSO4.H2O, and anhydrous (dry) forms. Anhydrous NaHSO4 is a dry granulated white powder, having a density of 2.74 g/ml with a melting point of 315 °C. Whereas, monohydrate is a white-colored granulated solid having density of 1.8 g/ml with a melting point of 59 °C. Monohydrate is considered a dry acid that is appropriate for safe storage and shipping. Its water solubility is 28.5 g/100 ml (25 °C) and 100 g/100 ml (100 °C) respectively. In general, if we talk about the molecular weight of NaHSO₄ it is 120.06 g/mol of anhydrous form. The melting point of sodium bisulphate is believed to be 150°C. 

Chemical Properties: Sodium Bisulfate is highly soluble in water. Aqueous solutions of NaHSO₄ are highly acidic in nature. Chemically it is an acidic salt, rather than a usual neutral salt. This is due to the replacement of only one acidic proton of the diprotic sulfuric acid. Aggressive reactions take place with strong oxidizing agents and strong bases. It stays in stable condition under ordinary conditions but decomposes instantly when contacted to water.

Preparation of Sodium Bisulfate

There are quite a few approaches for obtaining Sodium Bisulfate (NaHSO₄):-

1. The neutralization reaction of an acid with a base resulting in the formation of salt and water. NaHSO₄ can be prepared by the reaction of sulfuric acid (H2SO4) and sodium hydroxide (NaOH), but these elements must be reacted in a specific ratio: the acid should be available in plenty as compared to the base. 

H₂SO₄ + NaOH →  NaHSO₄ + H₂O

(Reaction is carried out with concentrated sulfuric acid. Reagents react in the ratio of 1:1.)

By the reaction of 2 moles of NaOH and 1 mole of H₂SO₄, sodium sulphate Na₂SO₄ forms:

H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O

(the protons of H₂SO₄ are completely replaced with Na ions and complete neutralization occurs, the product is normal salt)

2. The reaction of an acid oxide with an alkali (taking oxide in abundance will result in the formation of acid salt):

NaOH + SO₃   →     NaHSO₄

If sodium hydroxide (NaOH) is taken in abundance while carrying out this reaction, normal (Na₂SO₄) salt will be formed.

3. The reaction of normal salt and an acid:

Na₂SO₄ + H₂SO₄    →       2NaHSO₄.

Some acid salts are acquired by hydrolysis (reaction with water, in which the original substance breaks down to form new compounds). NaHSO₄ cannot be acquired from sulphate by hydrolysis, since this salt is originated by the strong base NaOH. Since H₂SO₄ and Na₂SO₄ does not react with water, but only gets dissolved in it. For example, NaHCO₃ is formed by strong base NaOH and the weak acid H₂CO₃.

Uses of Sodium Bisulfate

Sodium Bisulfate falls under the class of chemical compounds known as acid salts. At the time of its production, NaHSO₄ preserves one of the hydrogen ions of a raw material (sulfuric acid), thus obtaining the acidic properties. It is this acidic quality that classifies NaHSO₄ as a general acid for industrial uses. Simultaneously, it is considered as a special acid for a few applications because of its purity. NaHSO₄ is dry and granular which is readily soluble in water and commonly used for adjusting pH in many applications. In brief in the following points you will get the knowledge of most of the uses of sodium bisulphate:

• The water in the swimming pool is usually acidic and to lower the pH of water in the swimming pool, we use sodium bisulphate.

• For metal finishing also you can use sodium bisulphate.

• In the chicken house, you are required to lower or reduce the concentration of Salmonella and for this sodium, bisulphate can be used.

• Sodium bisulphate can be used to facilitate a reaction. Thus, it is a very good catalyst.

• Sodium bisulphate can be used as a bleaching agent.

• For manufacturing papers in the paper house, you can use sodium bisulfate.

• The treatment of water in the water treatment plants can use sodium sulphate.

• Sodium sulphate can be used in paints.

• Sodium sulphate can be used in agricultural chemicals.

• For the preparation of velvet clothes, you can use sodium bisulphite.

Preservative

Sodium bisulfate is commonly used as a preservative, food additive, in meat processing, in dietary supplements, and in drugs. It is used as a food additive to make the dough rise as well as being used in meat and poultry processing. Recently it is being used in the browning prevention of fresh-cut produce. It is also used as a general-use feed additive, including companion animal food.

Swimming Pool Application

Sodium Bisulfate is used for reducing pH levels in swimming pools and spas. NaHSO₄ is the safest product for use in homes, spas, and institutional pools. Generally, 1-2 lbs. are applied in a pool of capacity 10,000 gallons which adequately reduces the pH level. After one or two hours the pH is above 7.8, the treatment is repeated until the pH level is between 7.2 and 7.6.

Metal Finishing

NaHSO₄ is the chief component for dry acid bath formulations in metal cleaning. The common formula for most of the acidic baths includes salts of fluorides (5-10%), NaHSO₄ (90-95%) along with a surfactant (a substance that reduces surface tension). The concentration is normally 3 lbs. per gallon of water. At temperatures till 170°F., this bath has the capability to clean copper, brass, steel, nickel, zinc, aluminum, titanium, magnesium, and stainless steel. Typically used are for scale removal, pickling, etching, and rust removal.

Adjuvant

Sodium Bisulfate defends agricultural spray chemicals owing to alkaline hydrolysis in spray solutions. The effectiveness of agricultural pesticides is significantly lessened when added to water having high pH. NaHSO₄ functions mainly well with glyphosate (kills unnecessary grasses) to improve their usefulness. Acidification with Sodium Bisulfate is suggested as a substitute to ammonium sulfate ((NH₄) ₂SO₄) for use with several herbicides.

Water Treatment

Sodium Bisulfate is applied as a descaler in boilers, cooling towers, and also water pipes. Sodium Bisulfate cleans and adjusts pH level. If there is a requirement for waste treatment of an alkaline nature, Sodium Bisulfatehighly is recommended.

Concrete Washout

Sodium Bisulfate reduces alkalinity in “wash out” ponds which is formed due to concrete truck cleaning. Concrete companies are potential distributors. Representatives of JonesHamilton Co. technical service can recommend pH adjustments.

Leather Tanning

Sodium Bisulfate acts as an acidifier for leather compounds when combined with quebracho tannin. It is added with fillers and other chemicals for acidifying hides used in shoe sole leather.

What are the Safety Hazards of Sodium Bisulfate?

Due to its strong acidic nature, sodium bisulfate is very irritating to the eyes and skin. At high concentrations, it can cause serious eye damage upon contact. It can cause severe diarrhea and vomiting if swallowed and is very toxic in large amounts. Sodium hydrosulfite is a toxic, corrosive, and non-combustible compound. Inhaling, swallowing or skin contact causes severe injury or leads to death. Oh heating, it liberates irritating and toxic gases. Besides all this sodium bisulphate is really hazardous for our health. As you can see it can be corrosive, toxic and a non-combustible compound as well. If you have ever inhaled, swallowed or even skin contact with this compound it can cause serious injury and in some cases, it may even cause the death of a person. This compound radiates irritating as well as toxic gases which are really dangerous.