1、 Different definitions

（1）焦亞硫酸鈉為白色或黃色結晶粉末或小結晶，帶有強烈的SO2氣味，比重 1.4，溶于水，水溶液呈酸性，與強酸接觸則放出SO2而生成相應的鹽類， 久置空氣中，則氧化成Na2S2O6，故該產(chǎn)品不能久存。高于150攝氏度，即*解出SO2。

(1) Sodium pyrosulfite is a white or yellow crystalline powder or small crystal, with a strong smell of SO2, with a specific gravity of 1.4. It is soluble in water, and the aqueous solution is acidic. In contact with strong acid, SO2 will be released to generate corresponding salts. If it is placed in the air for a long time, it will be oxidized to na2s2o6, so the product cannot exist for a long time. Above 150 ℃, i.e. * SO2 is decomposed.

（2）亞硫酸鈉，又稱無水亞硫酸鈉、化學式Na2SO3，常見的亞硫酸鹽，白色、單斜晶體或粉末。對眼睛、皮膚、粘膜有刺激作用，可污染水源。

(2) Sodium sulfite, also known as anhydrous sodium sulfite, chemical formula Na2SO3, common sulfite, white, monoclinic crystal or powder. It can irritate eyes, skin and mucous membrane and pollute water sources.

受高熱*解產(chǎn)生有毒的硫化物煙氣。工業(yè)上主要用于制亞硫酸纖維素酯、硫代硫酸鈉、化學藥品、漂白織物等， 還用作還原劑、防腐劑、去氯劑等。

Toxic sulfide flue gas is produced by high thermal decomposition. In industry, it is mainly used to make cellulose sulfite, sodium thiosulfate, chemicals, bleached fabrics, etc. it is also used as reducing agent, preservative, dechlorinating agent, etc.

二、顏色、形狀不同

2、 Different colors and shapes

（1）焦亞硫酸鈉為白色或黃色結晶粉末或小結晶。

(1) Sodium pyrosulfite is white or yellow crystalline powder or small crystals.

（2）亞硫酸鈉：常見的亞硫酸鹽，白色、單斜晶體或粉末。

(2) Sodium sulfite: common sulfite, white, monoclinic crystal or powder.

三、作用不同

3、 Different functions

（1）醫(yī)藥工業(yè)用于生產(chǎn)氯仿、苯丙砜和苯甲醛。橡膠工業(yè)用作凝固劑。印染工業(yè)用作棉布漂白后的脫氯劑、棉布煮煉助劑。制革工業(yè)用于皮革處理，能使皮革柔軟、堅韌，具有防水、抗折、耐磨等性能。化學工業(yè)用于生產(chǎn)羥基香草醛、鹽酸羥胺等。感光工業(yè)用作顯影劑等。

(1) The pharmaceutical industry is used to produce chloroform, phenylpropanesulfone and benzaldehyde. The rubber industry is used as a coagulant. Printing and dyeing industry is used as dechlorination agent for cotton bleaching and cotton scouring assistant. Leather industry is used for leather treatment, which can make leather soft and tough, with waterproof, folding resistance, wear resistance and other properties. Chemical industry is used to produce hydroxyvanillin, hydroxylamine hydrochloride, etc. Photosensitive industry is used as developer, etc.

（2）用于碲和鈮的微量分析測定和顯影液的配制，還用作還原劑；用于人造纖維穩(wěn)定劑、織物漂白劑、照相顯影劑、染漂脫氧劑、香料和染料還原劑、造紙木質素脫除劑等；用作普通分析試劑和電阻材料。

(2) It is used for microanalysis and determination of tellurium and niobium and preparation of developing solution. It is also used as reducing agent; It is used as stabilizer for man-made fiber, fabric bleach, photographic developer, deoxidizer for dyeing and bleaching, reducing agent for perfume and dye, lignin remover for papermaking, etc; Used as common analytical reagent and resistance material.