Does salt absorb water3/16/2023 Point out that several water molecules can arrange themselves near an ion and help remove it from the crystal. Project the image Sodium Chloride Dissolving in Water. Show students a series of four pictures to help explain the process of water dissolving salt. Project an image and have students model what happens when salt dissolves in water.Arrange the ions on a piece of construction paper to represent a 2-D salt crystal.Activity sheet with sodium and chloride ions and water molecules.How does salt dissolve in water? Materials Look at the teacher version of the activity sheet to find the questions and answers. The Explain It with Atoms & Molecules and Take It Further sections of the activity sheet will either be completed as a class, in groups, or individually, depending on your instructions. Students will record their observations and answer questions about the activity on the activity sheet. Remind students that the green balls represent negative chloride ions and the gray balls represent positive sodium ions.Īsk students: What is it about water molecules and the ions in salt that might make water able to dissolve salt? The positive and negative polar ends of a water molecule are attracted to the negative chloride ions and positive sodium ions in the salt. Project the image Sodium Chloride Crystal. You may choose to laminate the water molecules, sodium ions, and chloride ions located on the last page of the activity sheet so that you can reuse them with your students next year. Alcohol should be disposed of according to local regulations. Read and follow all warnings on the label. Keep it away from flames or spark sources. Safetyīe sure you and the students wear properly fitting goggles. The activity sheet will serve as the “Evaluate” component of each 5-E lesson plan. Evaluationĭownload the student activity sheet, and distribute one per student when specified in the activity. Students will also be able to explain why a less polar liquid, such as alcohol, is not good at dissolving salt. Students will be able to identify the variables in their experiment. Students will be able to explain, on the molecular level, why water can dissolve salt. They will relate their observations to the structure of salt, water, and alcohol on the molecular level. After seeing an animation of water dissolving salt, students will compare how well water and alcohol dissolve salt. Students will make a 2-D model of a salt crystal and use water molecule cut-outs to show how water dissolves salt. The substance being dissolved is called the solute, and the substance doing the dissolving is called the solvent.The amount of a substance that can dissolve in a liquid (at a particular temperature) is called the solubility of the substance.Water can dissolve salt because the positive part of water molecules attracts the negative chloride ions and the negative part of water molecules attracts the positive sodium ions.Salt (sodium chloride) is made from positive sodium ions bonded to negative chloride ions.The polarity of water molecules enables water to dissolve many ionically bonded substances.
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