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化学方程式是用分子式来表示化学反应的式子。学生能否正确书写化学方程式,往往是考察学生基本功的一个重要标准。同时这也是学生必须熟练掌握的基本技能。下面谈谈书写化学方程式的注意事项:1.写化学方程式必须以实验事实为依据。应确切知道反应物和生成物,在等号两边分别写出它们的分子式,并加以配平。2.写化学方程式不能想当然,无原则地类推,例如一些活泼金属与稀酸(盐酸或硫酸)反应时会放出氢气,并得到此金属的盐。
The chemical equation is a formula that expresses a chemical reaction. Whether students can correctly write chemical equations is often an important criterion for examining students’ basic skills. At the same time, this is the basic skill that students must master. Here are some notes on writing chemical equations: 1. Writing chemical equations must be based on experimental facts. Reactants and products should be known exactly and their molecular formulae are written on both sides of the equal sign and trimmed. 2. The equations for writing chemical equations cannot be taken for granted, without analogy. For example, when some reactive metals react with dilute acids (hydrochloric acid or sulfuric acid), hydrogen is evolved and salts of this metal are obtained.