Sodium chloride

NaCl, AR 99.5%, CAS : 7647-14-5

Sodium chloride, commonly known as table salt, has various applications in secondary school science experiments. Here are a few examples:

1. Solubility: Students can explore the solubility of sodium chloride in different solvents like water, alcohol, or oil. They can compare the rate and extent of dissolution and study the factors affecting solubility, such as temperature and agitation.

2. Freezing point depression: Sodium chloride can be used to demonstrate the concept of freezing point depression. By adding sodium chloride to water and measuring the freezing point, students can observe how the presence of a solute lowers the freezing point of a solvent.

3. Electrolysis: Sodium chloride can be used in electrolysis experiments to study the process of electrolysis and the formation of chlorine gas and sodium hydroxide. By passing an electric current through a sodium chloride solution, students can observe the products of electrolysis at the electrodes.

4. Crystal growth: Sodium chloride can be used to grow salt crystals. Students can create a saturated solution of sodium chloride and promote crystal growth through evaporation. This allows them to observe crystal formation and discuss factors influencing crystal size and shape.

These experiments provide students with hands-on experience in solubility, freezing point depression, electrolysis, and crystal growth, helping them understand fundamental concepts in chemistry and develop practical skills.

Sodium chloride 氯化鈉，俗稱食鹽，在中學科學實驗有多種應用。 這裡有一些例子：

1. 溶解度：學生可以探討氯化鈉在水、酒精或油等不同溶劑中的溶解度。 他們可以比較溶解的速率和程度，並研究影響溶解度的因素，例如溫度和攪拌。

2. 冰點降低：氯化鈉可以用來示範冰點降低的概念。 透過將氯化鈉添加到水中並測量凝固點，學生可以觀察溶質的存在如何降低溶劑的凝固點。

3.電解：氯化鈉可用於電解實驗，研究電解的過程及氯氣和氫氧化鈉的形成。 透過使電流通過氯化鈉溶液，學生可以觀察電極上的電解產物。

4.晶體生長：氯化鈉可用於生長鹽晶體。 學生可以創建飽和氯化鈉溶液並透過蒸發促進晶體生長。 這使他們能夠觀察晶體形成並討論影響晶體尺寸和形狀的因素。

這些實驗為學生提供了溶解度、冰點降低、電解和晶體生長的實務經驗，幫助他們理解化學的基本概念並培養實務技能。