NATRI SULFAT KHAN

Natrii sulfas exsiccatus

Na2SO4 P.t.l: 142,0

Natri sulfat khan phai cha t 98,5 en 101,0% Na2SO4, tnh theo che pham a lam kho.

Tnh chat

Bot trang, de hut am. De tan trong nc.

nh tnh

A. Che pham phai cho phan ng cua ion natri va sulfat (Phu luc 8.1).

B. Che pham phai ap ng phep th Mat khoi lng do lam kho.

o trong va mau sac cua dung dch

Dung dch S: Hoa tan 2,2 g che pham trong nc khong co carbon dioxyd (TT) va pha loang thanh 100 ml vi cung dung moi.

Dung dch S phai trong (Phu luc 9.2) va khong mau (Phu luc 9.3, phng phap 2).

Gii han acid - kiem

Them vao 10 ml dung dch S 0,1 ml dung dch xanh bromothymol (TT). e lam chuyen mau dung dch nay, khong c dung qua 0,5 ml dung dch natri hydroxyd 0,01 M (C) hoac dung dch acid hydrocloric 0,01 M (C).

Clorid

Khong c qua 0,045% (Phu luc 9.4.5).

Lay 5 ml dung dch S, pha loang vi nc thanh 15 ml va tien hanh th.

Arsen

Khong c qua 5 phan trieu (Phu luc 9.4.2).

Lay 10 ml dung dch S va tien hanh th theo phng phap A.

Calci

Khong c qua 0,045% (Phu luc 9.4.3).

Lay 10 ml dung dch S, pha loang vi nc thanh 15 ml va tien hanh th.

Kim loai nang

Khong c qua 45 phan trieu (Phu luc 9.4.8).

Lay 12 ml dung dch S, tien hanh th theo phng phap 1. Dung dung dch ch mau 1 phan trieu (TT) e chuan b mau oi chieu.

Sat

Khong c qua 90 phan trieu (Phu luc 9.4.13).

Lay 5 ml dung dch S, pha loang vi nc thanh 10 ml va tien hanh th.

Magnesi

Khong c qua 0,02%.

Them vao 10 ml dung dch S 1 ml glycerin 85% (TT), 0,15 ml dung dch vang titan (TT), 0,25 ml dung dch amoni oxalat 4% (TT) va 5 ml dung dch natri hydroxyd 2 M (TT), lac eu. Dung dch nay neu co mau hong th khong c am hn mau cua dung dch oi chieu c chuan b ong thi trong cung ieu kien, nhng thay dung dch S bang hon hp 5 ml dung dch magnesi mau 10 phan trieu (TT) va 5 ml nc.

Mat khoi lng do lam kho

Khong c qua 0,5% (Phu luc 9.6).

(1,000 g; 130 oC).

nh lng

Hoa tan 0,100 g che pham trong 40 ml nc. Them vao hon hp gom co 0,2 ml dung dch acid hydrocloric (TT) va 80 ml methanol (TT). Chuan o bang phng phap chuan o o ien the (Phu luc 10.2), dung dung dch ch nitrat 0,1 M (C), ien cc chon loc ch lam ien cc ch th va ien cc bac bac clorid lam ien cc oi chieu.

1 ml dung dch ch nitrat 0, 1 M (C) tng ng vi 14,20 mg Na2SO4.

Bao quan

ng trong chai, lo kn, tranh hut am.