NATRI HYDROCARBONAT

Natrii hydrocarbonas

NaHCO3 P.t.l: 84,0

Natri hydrocarbonat phai cha t 99,0 en 101,0% NaHCO3.

Tnh chat  

Bot ket tinh trang. Tan trong nc, thc te khong tan trong ethanol 96%. Khi un nong trang thai kho hoac trong dung dch, no chuyen dan thanh natri carbonat.

nh tnh  

A. Them vao 5 ml dung dch S 0,1 ml dung dch phenolphtalein (TT), mau hong nhat xuat hien. un nong, kh bay len va dung dch co mau o.

B. Dung dch S phai cho phan ng cua carbonat va bicarbonat (Phu luc 8.1).

C. Dung dch S phai cho phan ng (A) cua ion natri (Phu luc 8.1).

o trong va mau sac cua dung dch  

Dung dch S: Hoa tan 5,0 g che pham trong 90 ml nc khong co carbon dioxyd (TT) va pha loang thanh 100,0 ml bang cung dung moi.

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

Carbonat   

pH cua dung dch S va mi pha phai khong c ln hn 8,6 (Phu luc 6.2).

Clorid  

Khong c qua 0,015% (Phu luc 9.4.5).

Them vao 7 ml dung dch S, 2 ml acid nitric (TT), pha loang thanh 15 ml bang nc va tien hanh th.

Sulfat  

Khong c qua 0,015% (Phu luc 9.4.14).

Them acid hydrocloric (TT) vao hon dch cha 1,0 g che pham trong 10 ml nc en khi trung tnh va tha khoang 1 ml roi pha loang thanh 15 ml bang nc va tien hanh th.

Amoni  

Khong c qua 20 phan trieu (Phu luc 9.4.1).

Lay 10 ml dung dch S pha loang thanh 15 ml bang nc va tien hanh th theo phng phap A. Dung hon hp gom 5 ml nc va 10 ml dung dch amoni mau 1 phan trieu (TT) e chuan b mau oi chieu.

Arsen  

Khong c qua 2 phan trieu (Phu luc 9.4.2).

Lay 0,5 g che pham tien hanh th theo phng phap A.

Calci  

Khong c qua 0,01% (Phu luc 9.4.3).

Them acid hydrocloric (TT) vao hon dch cha 1,0 g che pham trong 10 ml nc cho en khi trung tnh, pha loang thanh 15 ml bang nc va tien hanh th.

Kim loai nang  

Khong c qua 10 phan trieu (Phu luc 9.4.8).

Hoa tan 2,0 g che pham trong hon hp gom 2 ml acid hydrocloric (TT) va 18 ml nc. Lay 12 ml dung dch nay tien hanh th theo phng phap 1. Dung dung dch ch mau 1 phan trieu lam mau oi chieu.

Sat  

Khong c qua 20 phan trieu (Phu luc 9.4.13).

Hoa tan 0,5 g che pham trong 5 ml dung dch acid hydrocloric loang (TT), pha loang thanh 10 ml bang nc va tien hanh th.

nh lng  

Hoa tan 1,500 g che pham trong 50 ml nc khong co carbon dioxyd (TT). Chuan o bang dung dch acid hydrocloric 1 M (C), dung 0,2 ml dung dch da cam methyl (TT) lam ch th.

1 ml dung dch acid hydrocloric 1 M (C) tng ng vi 84,0 mg NaHCO3.

 

Bảo quản

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