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Give two physical properties shared by all states - Leaving Cert Chemistry - Question A - 2016
Question A
Give two physical properties shared by all states. Or (a) Describe what happens when salt is dissolved in water using the particle model. In your answer, you shoul... show full transcript
Worked Solution & Example Answer:Give two physical properties shared by all states - Leaving Cert Chemistry - Question A - 2016
Step 1
Give two physical properties shared by all states.
Answer
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Mass: All states of matter (solid, liquid, gas) have mass, which is a measure of the amount of matter contained within them.
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Volume: All states have a volume, which is the amount of space they occupy. Solids have a fixed volume, liquids take the shape of their container while maintaining volume, and gases expand to fill the volume of their container.
Step 2
Describe what happens when salt is dissolved in water using the particle model.
Answer
When salt (sodium chloride, NaCl) is dissolved in water, the process can be explained through the particle model:
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Separation of Particles: The ionic bonds between the sodium (Na⁺) and chloride (Cl⁻) ions in the salt crystal are broken when it comes into contact with water.
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Role of Water Molecules: Water molecules, which are polar, interact with the ions. The oxygen end of the water molecule, which has a slight negative charge, is attracted to the positively charged sodium ions. Conversely, the hydrogen ends of the water molecules, which have a slight positive charge, are attracted to the negatively charged chloride ions.
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Solvation Process: This attraction allows the water molecules to surround and separate the individual sodium and chloride ions, a process known as solvation. As more salt dissolves, the ions disperse throughout the solution, leading to a homogeneous mixture.
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Resulting Solution: The dissolved salt remains in solution as ions, ensuring that the overall structure of the liquid remains consistent while the characteristics of the solution change due to the presence of the dissolved ions.