This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1910 edition. Excerpt: ... 81 per cent barium. What is the formula? Ans. Ba02. 133. Derive the formula of the crystallized salt which, by analysis, gave the percentage composition: 19.98 per cent iron, 11.47 per cent sulphur, 5.24 per cent hydrogen, 63.31 per cent oxygen, 10 grams of this crystallized salt lost 4.5 grams of water upon dehydration. Ans. FeS04. 7 H20. 134. The percentage composition of a certain salt is: 15.6 per cent chromium, 14.41 per cent sulphur, 4.79 per cent hydrogen, 65.2 per cent oxygen. 10 grams of the crystallized salt lost 4 grams of water upon dehydration and gave a residue of Cr2(S04)3. What is the formula? Ans. Cr2(S04), . 15 H20 135. The percentage composition of a certain salt is: 27.51 per cent calcium, 22.15 per cent sulphur, 1.02 per cent hydrogen, 49.32 per cent oxygen. 10 grams of this crystallized salt lost 0.6 gram of water upon dehydration. What is the formula? Ans. (CaS04)a. H20. 136. 2.5 grams of a crystallized salt known to be a sulphate of iron, and containing 20 per cent of iron, lost 1.13 grams of water upon dehydration. What is the formula? Ans. FeSO.. 7 H20. CHAPTER IX. CALCULATIONS DEPENDING UPON CHEMICAL EQUATIONS. In calculations which depend upon chemical reactions, the equations representing these reactions must first be constructed. In all chemical equations the number of atomic weights of any one element concerned remains a constant; the relative amount of each element, therefore, will be alike for both sides of the equation. Naturally the valence of each element in the reaction under consideration must be known, as upon these factors the balancing of equations is dependent. This valence or measure by which each atom of any element can enter into combination determines, accordingly, the number of other atoms or groups..