what is sodium metabisulfite

{"title":"Sodium Metabisulfite Heavy Metal As Pb Ppm 2.0 Packaging Iron Drum","imgUrl":"https:\/\/img.silkroadsl.com\/nimg\/b8\/e4\/d0b00b122dff3aa935c7b86a3f5c-200x200-1.jpg","attrs":{"Price":"USD $2260","Brand Name":"Y&X","Model Number":"D481","Minimum Order Quantity":"1","Delivery Time":"5-8 days","Certification":"ISO9001","Place of Origin":"China","Payment Terms":"T\/T, L\/C","Packaging Details":"standard package shipping","Production Appearance":"White Powder","Technical Specification, Water Insoluble":"0.05% max","Na2S2O5 (%), Specifications":"96.5 Min.","Heavy Metal(as Pb) (ppm), Typical Analysis":"2.0","Purity":"90%","FAQ, Payment Terms and Packaging Details":"The payment terms for the Xanthate Flotation product are T\/T and L\/C. The packaging details include wooden box, iron drum, and ton bag packing.","MOLECULAR FORMULA":"Na2S2O5","FAQ, Minimum Order Quantity":"The minimum order quantity for the Xanthate Flotation product is 1 ton."}}

{"title":"metabisulfitedesodium\/Sodium Metabisulphite\/as food preservatives and decolorizer","imgUrl":"https:\/\/img.silkroadsl.com\/nimg\/d0\/6d\/b550b1e42504078b6619db6b5840-200x200-1.jpg","attrs":{"Price":"1~300","Brand Name":"Hengchang","Model Number":"SMB-11","Minimum Order Quantity":"1MT Sodium Metabisulfiate\/Sodium Pyrosulfite","Delivery Time":"2 weeks \/Sodium Metabisulfiate\/Sodium Pyrosulfite","Place of Origin":"China","Certification":"ISO9001:2008","Packaging Details":"25kg.750kg.1000kg.1250kg Sodium Metabisulfiate\/Sodium Pyrosulfite","Payment Terms":"T\/T or L\/C at sight\/Sodium Metabisulfiate\/Sodium Pyrosulfite","Supply Ability":"500MT\/week Sodium Metabisulfiate\/Sodium Pyrosulfite"}}