Why does salt attract water

If your plan is to get rid of the humidity in a damp basement, start with a pound bag of sodium chloride to make your rock salt dehumidifier.

When a cucumber is placed in a strong salt solution, the resulting pickles are shriveled. This is because the cucumber tends to lose water when placed in such an environment.

Fermentation still occurs, though at a rather slow rate. Answer: it loses water through osmosis and reacts with air. If you place a cucumber in distilled water, it would eventually wither and die, because distilled water has none of the solvents that the cucumber needs to fuel its cells. The salt water cucumber has gone down to 21 grams, and it feels quite sort of squishy and flabby. But the distilled water cucumber has gone up to 30 grams.

The critical water content of sodium chloride NaCl is 0. Salt absorbs water moisture because it is an ionic compound with strong attractive forces for the highly polar water molecules. Once this happens, the salt is dissolved, resulting in a homogeneous solution.

Biochemical Properties of Water - Advanced. Skip to main content. Search Search. Water molecules and their interaction with salt. The putative reaction is. While this reaction could proceed in theory, it is extremely energetically unfavorable. This is because HCl is a much stronger acid than water and happily sheds its proton in solutions with acidity far greater than that of water, which has a neutral pH of 7.

Already noted was the polarity of both the water molecule, which you can imagine as roughly boomerang-shaped, and the NaCl molecule, which looks more like a short dumbbell. When table salt is placed in water, the slightly electropositive sodium portion is attracted to the slightly electronegative oxygen portion of water molecules.

At the same time, the slightly electronegative chlorine portion of NaCl is attracted to the slightly electropositive hydrogen portion of water. In neither case is a true bond created, but the attractions set up a "tug-of-war" in which the ionic bonds of NaCl and the covalent bonds of H 2 O are both strained.

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Students will make a 2-D model of a salt crystal and use water molecule cut-outs to show how water dissolves salt. After seeing an animation of water dissolving salt, students will compare how well water and alcohol dissolve salt.

They will relate their observations to the structure of salt, water, and alcohol on the molecular level. Students will be able to explain, on the molecular level, why water can dissolve salt.

Students will be able to identify the variables in their experiment. Students will also be able to explain why a less polar liquid, such as alcohol, is not good at dissolving salt. Download the student activity sheet , and distribute one per student when specified in the activity. Be sure you and the students wear properly fitting goggles. Isopropyl alcohol is flammable. Keep it away from flames or spark sources.

Read and follow all warnings on the label. Alcohol should be disposed of according to local regulations. 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. Project the image Sodium Chloride Crystal. Remind students that the green balls represent negative chloride ions and the gray balls represent positive sodium ions.

Students will record their observations and answer questions about the activity on the activity sheet. Look at the teacher version of the activity sheet to find the questions and answers. Project the image Sodium Chloride Dissolving in Water. Point out that several water molecules can arrange themselves near an ion and help remove it from the crystal.

Show students that the positive area of a water molecule will be attracted to the negative chloride ion and that the negative area of a water molecule will be attracted to the positive sodium ion. Look at the pictures showing how water molecules dissolve salt.

Then arrange the water molecules around the sodium and chloride ions in the correct orientation. The positive part of the water molecules should be near the negative chloride ion. The negative part of the water molecules should be near the positive sodium ion. Project the animation Sodium Chloride Dissolving in Water.