heat of sublimation

简明释义

升华热

英英释义

例句

1.Understanding the heat of sublimation is crucial for designing effective freeze-drying processes.

理解升华热对于设计有效的冷冻干燥过程至关重要。

2.In a vacuum, the heat of sublimation can be measured to determine the purity of a substance.

在真空中，可以测量升华热来确定物质的纯度。

3.Chemists often calculate the heat of sublimation to understand how substances behave under different temperatures.

化学家们经常计算升华热以了解物质在不同温度下的行为。

4.The process of drying ice involves the release of the heat of sublimation, which is the energy required for it to change from solid to gas.

干冰的干燥过程涉及到升华热的释放，即其从固体变为气体所需的能量。

5.The heat of sublimation for carbon dioxide is significant when considering its use in refrigeration systems.

考虑二氧化碳在制冷系统中的使用时，其升华热是显著的。

作文

Sublimation is a fascinating process that occurs when a solid transitions directly to a gas without passing through the liquid phase. This phenomenon can be observed in various substances, such as dry ice (solid carbon dioxide) and iodine. One of the key concepts associated with sublimation is the heat of sublimation, which refers to the amount of energy required to convert a unit mass of a solid into a gas at constant temperature and pressure. Understanding this concept is crucial not only in the field of chemistry but also in various industrial applications.The heat of sublimation plays a significant role in determining the conditions under which sublimation occurs. For example, when dry ice is exposed to room temperature, it absorbs heat from the surroundings, leading to its transition from a solid to a gaseous state. The energy absorbed during this process is quantified by the heat of sublimation. This energy is essential for overcoming the intermolecular forces that hold the solid together, allowing the molecules to escape into the gas phase.In practical terms, the heat of sublimation has important implications in various scientific and industrial contexts. For instance, in the food industry, sublimation is utilized in freeze-drying processes. During freeze-drying, food is first frozen and then subjected to low pressure, allowing the ice to sublimate directly into vapor. The heat of sublimation is a critical factor in this process, as it influences how much energy is needed to remove moisture from the food without compromising its quality.Moreover, understanding the heat of sublimation can aid in predicting the behavior of substances under different environmental conditions. For example, in meteorology, the sublimation of ice and snow can affect local climates and weather patterns. When snow sublimates, it releases water vapor into the atmosphere, which can contribute to cloud formation and precipitation. Therefore, knowing the heat of sublimation of snow can help meteorologists make more accurate predictions about weather changes.Additionally, the heat of sublimation is relevant in the study of planetary atmospheres. For instance, on Mars, the presence of polar ice caps made of carbon dioxide raises questions about the sublimation processes occurring there. By studying the heat of sublimation of CO2 ice, scientists can better understand the seasonal changes on Mars and the potential for past or present life.In conclusion, the heat of sublimation is a vital concept that intersects various fields of science and technology. Its implications range from industrial processes like freeze-drying to natural phenomena in meteorology and planetary science. A deeper understanding of this concept not only enhances our knowledge of physical chemistry but also enables us to harness sublimation for practical applications. As we continue to explore the properties of materials and their behaviors under different conditions, the heat of sublimation will undoubtedly remain a key focus of research and innovation.

升华是一个迷人的过程，它发生在固体直接转变为气体而不经过液相的情况下。这种现象可以在各种物质中观察到，例如干冰（固态二氧化碳）和碘。与升华相关的一个关键概念是升华热，它指的是在恒定温度和压力下，将单位质量的固体转化为气体所需的能量。理解这一概念不仅在化学领域至关重要，而且在各种工业应用中也非常重要。升华热在确定升华发生的条件方面发挥着重要作用。例如，当干冰暴露于室温时，它会从周围环境中吸收热量，导致其从固态转变为气态。在这个过程中吸收的能量由升华热来量化。这种能量对于克服将固体保持在一起的分子间力至关重要，使分子能够逃逸到气相中。在实际应用中，升华热在各种科学和工业背景下具有重要意义。例如，在食品工业中，升华被用于冷冻干燥过程。在冷冻干燥过程中，食物首先被冷冻，然后在低压下进行处理，使冰直接升华为蒸汽。升华热是这个过程中的一个关键因素，因为它影响去除食物水分所需的能量，而不会影响其质量。此外，理解升华热可以帮助预测物质在不同环境条件下的行为。例如，在气象学中，冰雪的升华可以影响当地气候和天气模式。当雪升华时，它会将水蒸气释放到大气中，这可能有助于云的形成和降水。因此，了解雪的升华热可以帮助气象学家更准确地预测天气变化。此外，升华热在行星大气的研究中也具有相关性。例如，在火星上，由于存在由二氧化碳构成的极地冰盖，因此对那里的升华过程提出了疑问。通过研究CO2冰的升华热，科学家可以更好地理解火星上的季节变化以及过去或现在生命的潜力。总之，升华热是一个重要的概念，交叉涉及多个科学和技术领域。它的影响范围从冷冻干燥等工业过程到气象学和行星科学中的自然现象。对这一概念的深入理解不仅增强了我们对物理化学的知识，而且使我们能够利用升华进行实际应用。随着我们继续探索材料的性质及其在不同条件下的行为，升华热无疑将继续成为研究和创新的重点。