doc__table__158

Calculation method HP 3 (fifth indent) 1. Write a balanced equation for the reaction that produces the gas. The general form of this equation should be as follows: rR + wW → pP + gG where R is the H260/H261 substance, W is water, P is a product of the reaction, and G is the gas released; r, w, p and g are the stoichiometric ratios that balance the equation. 2. Attribute molecular weights and stoichiometric ratios to the substances in the equation. 3. Divide (r × molar weight of R) by (g × 22,4). This gives the mass of R that will evolve 1 litre of gas. 1 mol of gas occupies 22,4 litres at standard temperature and pressure. 4. Divide this amount (in grams) by 1 000 (to convert to kilograms) and multiply it by 100 to give a percentage by weight, and thus the limiting concentration for HP 3 (fifth indent) of substance R. Example calculation: A waste contains aluminium carbide. Aluminium carbide is a H260 substance which reacts with water to give methane gas. Al4C3 + 6H2O → 2Al2O3 + 3CH4 aluminium carbide water aluminium oxide methane 144 g 18 g 102 g 16 g 1 mol 6 mol 2 mol 3 mol r = 1 mol of Al4C3, R = 144 g; g = 3 mol CH4. Limiting concentration of aluminium carbide in waste = [144 / (3 × 22,4)] / 1 000 × 100, which is 0,21 % (approximately 0,2 %).

← d1e507-87-1__para__18 · All articles · d1e507-87-1__para__19 →

Source: EUR-Lex (Cellar) · retrieved 2026-09-25 · Text as adopted (Official Journal); later amendments are not incorporated in this text.