molecular weight

简明释义

分子量

英英释义

例句

1.In biochemistry, the molecular weight of proteins can vary significantly depending on their structure.

在生物化学中，蛋白质的分子量可能会因其结构而有显著差异。

2.The molecular weight of glucose is about 180 g/mol, which is important for understanding its role in metabolism.

葡萄糖的分子量约为180克/摩尔，这对于理解其在代谢中的作用非常重要。

3.Chemists often use the molecular weight to determine the amount of a substance needed for a reaction.

化学家通常使用分子量来确定反应中所需物质的量。

4.When calculating the molecular weight of a compound, you must consider the atomic weights of each element in its formula.

在计算一个化合物的分子量时，必须考虑其公式中每个元素的原子量。

5.The molecular weight of water is approximately 18 g/mol, which means it consists of two hydrogen atoms and one oxygen atom.

水的分子量大约为18克/摩尔，这意味着它由两个氢原子和一个氧原子组成。

作文

Understanding the concept of molecular weight is essential in the field of chemistry, as it plays a crucial role in various scientific applications. The term molecular weight refers to the mass of a molecule, typically measured in atomic mass units (amu) or grams per mole (g/mol). It is calculated by summing the atomic weights of all the atoms present in a molecule. For instance, consider water (H2O), which consists of two hydrogen atoms and one oxygen atom. The atomic weight of hydrogen is approximately 1 amu, and that of oxygen is about 16 amu. Therefore, the molecular weight of water can be calculated as follows: (2 x 1) + (1 x 16) = 18 amu.The significance of molecular weight extends beyond mere calculations; it is fundamental in determining the behavior of substances in chemical reactions. For example, when chemists conduct experiments, they often need to know the molecular weight of reactants to calculate the correct proportions for a reaction. This is crucial in stoichiometry, where the ratios of reactants and products are determined based on their molecular weights.Moreover, molecular weight influences properties such as solubility, boiling point, and melting point. Substances with higher molecular weights tend to have higher boiling and melting points due to stronger intermolecular forces. This principle is evident when comparing small molecules like methane (CH4), which has a low molecular weight of 16 g/mol, to larger molecules like octane (C8H18), which has a much higher molecular weight of 114 g/mol. As a result, octane has a significantly higher boiling point than methane.In addition, molecular weight is vital in biochemistry, particularly in understanding macromolecules such as proteins and nucleic acids. Proteins, for example, are made up of amino acids, each with its own molecular weight. The total molecular weight of a protein can provide insights into its structure and function. Enzymes, which are specialized proteins, often require specific molecular weights to perform their catalytic functions effectively.Furthermore, the determination of molecular weight is essential in pharmaceuticals. When developing medications, scientists must ensure that the molecular weight of active ingredients is appropriate for effective absorption and distribution in the body. A drug with an unsuitable molecular weight may not interact properly with biological systems, leading to reduced efficacy or increased side effects.In conclusion, the concept of molecular weight is a cornerstone of chemistry and related fields. Its implications are vast, affecting everything from basic chemical reactions to complex biological processes. By mastering the understanding of molecular weight, students and professionals alike can enhance their grasp of chemical principles and apply this knowledge in practical scenarios, ultimately contributing to advancements in science and technology.

理解分子量的概念在化学领域至关重要，因为它在各种科学应用中发挥着关键作用。术语分子量指的是分子的质量，通常以原子质量单位（amu）或克每摩尔（g/mol）进行测量。它是通过将分子中所有原子的原子量相加来计算的。例如，考虑水（H2O），它由两个氢原子和一个氧原子组成。氢的原子量约为1 amu，氧的原子量约为16 amu。因此，水的分子量可以这样计算：（2 x 1）+（1 x 16）= 18 amu。分子量的重要性不仅仅在于简单的计算；它对于确定物质在化学反应中的行为至关重要。例如，当化学家进行实验时，他们常常需要知道反应物的分子量以计算反应的正确比例。这在化学计量学中至关重要，反应物和产物的比率是基于它们的分子量来确定的。此外，分子量影响溶解度、沸点和熔点等属性。具有较高分子量的物质往往由于更强的分子间作用力而具有更高的沸点和熔点。这一原理在比较小分子如甲烷（CH4）时尤为明显，甲烷的分子量为16 g/mol，而较大分子如辛烷（C8H18）的分子量则高达114 g/mol。因此，辛烷的沸点显著高于甲烷。此外，分子量在生物化学中至关重要，特别是在理解蛋白质和核酸等大分子时。蛋白质例如，由氨基酸组成，每种氨基酸都有其自身的分子量。蛋白质的总分子量可以提供对其结构和功能的深入见解。酶是特殊的蛋白质，通常需要特定的分子量才能有效地执行催化功能。此外，分子量的测定在制药中至关重要。在开发药物时，科学家必须确保活性成分的分子量适合有效吸收和分布在体内。不合适的分子量的药物可能无法与生物系统正确相互作用，导致疗效降低或副作用增加。总之，分子量的概念是化学及相关领域的基石。其影响范围广泛，从基本的化学反应到复杂的生物过程。通过掌握对分子量的理解，学生和专业人士都可以增强对化学原理的掌握，并在实际场景中应用这些知识，最终为科学和技术的进步做出贡献。