Qualitative analysis / by William Briggs and R.W. Stewart.

  • William Briggs
Date:
1913
Catalogue details

Licence: Public Domain Mark

Credit: Qualitative analysis / by William Briggs and R.W. Stewart. Source: Wellcome Collection.

    84/180 (page 68)
    contains the acid as sodium nitrate, the base having been precipitated as a carbonate. FeS04 + Na2C03 = FeC03 + Na2S04. 2. Heat with concentrated sulphuric acid and copper turnings: nitric oxide, NO, is given off, which is con¬ verted into brown fumes of nitrogen peroxide, N02, in the upper part of the tube, from absorption of oxygen. 3 Cu + 8 H2S04 + 8 KNOs = 3 Cu(N03)2 + 8 KHS04 + 4 HoO + 2 NO. 2 NO + 02 = 2 NOo. 3. A nitrate heated on charcoal deflagrates. Note.-—All nitrates are soluble in water; hence we have no precipitation reactions. Compare chloric acid. NITROUS ACID, HN02. Solution—Potassium Nitrite, KN02. 1. On addition of dilute sulphuric acid, H2S04, a brown gas is given off, which consists of a mixture of NO, and NO. 2 kno2 + h2so4 = k2so4 + NO + no2 + h2o. In the upper part of the tube the NO combines with the oxygen of the air and becomes converted into nitrogen peroxide, N02. [No gas is evolved when nitrates are mixed with dilute sulphuric acid.] 2. A solution of ferrous sulphate gives a dark b'own coloration on the addition of dilute sulphuric acid. [Dis¬ tinction from HN03.j The coloration is due to the formation of the compound FeS04, NO. 2 FeS04 + 2 KNOo + 3 H2 S04 = Fe3(S04)3 + 2 KHS04 + 2 H20 + 2 NO. FeS04 + NO = FeS04, NO.