Flashcards
Topic 4.1 Miscibility and Solutions
Cards in this deck (26)
- 1What can solvents be considered as? Give examplesPolar (e.g. water, methanol) or non-polar (e.g. hexane, turpentine, petrol)
- 2Polar and non-polar solvents do not readily mixPolar and non-polar solvents do not readily mix
- 3Are polar or non-polar molecules more soluble in water?Highly polar molecular substances are more soluble in water than nonpolar molecules of a similar size.
- 4Are smaller or larger molecules more soluble in water?Molecular substances with small molecules are more soluble in water than larger molecules of similar polarity.
- 5What facilitates the mixing of polar and non-polar substances?Compounds with non-polar and polar or ionic components facilitate the mixing of polar and non-polar substances.
- 6Why is water said to be a good solvent?Many substances can dissolve in it.
- 7What is the name of the substance that dissolves in water?It is called a solute.
- 8When a solute dissolves in a solvent what is the resulting mixture called?A solution.
- 9When water is the solvent in a solution, what is the solution often referred to as?Aqueous solution
- 10what happens to the particles when a solid dissolves in a solvent to form a solution? Draw and explain.The solute particles are uniformly distributed throughout the solvent.
- 11Solubility is related to the secondary interactions between water and other substances when dissolving occurs are: Dipole – dipole interactions Hydrogen bonding Ion-dipole interactionsSolubility is related to the secondary interactions between water and other substances when dissolving occurs are:
Dipole – dipole interactions
Hydrogen bonding
Ion-dipole interactions - 12What is and what determines polarity?Polarity is determined by the distribution of atoms within a molecule, and therefore a dipole associated with the uneven sharing of electrons, creating a delta positive and delta negative dipole.
- 13What factors make it a polar molecule?If there are different types of atoms present AND the molecule is non symmetrical, then the molecule itself is a polar molecule.
- 14Explain why water is a common polar solventThere is a difference in electronegativity between the oxygen atom and the two hydrogen atoms and the molecule is a V-shape, and s the dipoles do not cancel out – thus water is polar
- 15Define miscibilityThe ability of one liquid to mix with another liquid.
- 16What are the key points you need to remember for miscibility?- Common non-polar solvents include the liquid hydrocarbons, which do have a polar bond, but can have a repetition of tetrahedral structure- so are overall non polar.
- In general, a polar compound will dissolve in a polar solvent and a non-polar compound will dissolve in a non-polar solvent - 17For a compound to dissolve in water what must it have?For a compound to dissolve in water, it must be able to form a secondary bonding network with the water molecules. The molecules must be ‘accepted’ into the secondary bonding network of water, forming a series of interactions with the water dipoles.
- 18Some solutes dissolve quickly in water while others dissolve slowly.Some solutes dissolve quickly in water while others dissolve slowly.
- 19What process do you use to speed up the dissolving rate of a solute?1. Grind the solute into smaller pieces to form a powder.
2. Heat the solution.
3. Shake or stir the solution. - 20A number of substances do not dissolve in water. They keep their shape because they have strong forces between their particles that cannot be overcome by secondary interactionsA number of substances do not dissolve in water. They keep their shape because they have strong forces between their particles that cannot be overcome by secondary interactions
- 21How is the amount of solute in a solution expressed?It is expressed in terms of concentration.
- 22What is the concentration related to?The concentration is related to the mass of the solute and the volume of solvent.
- 23There is a limit as to how much of a solute can be dissolved in a solvent. When a points reached where no more solute will dissolve, the solution is said to be saturated.There is a limit as to how much of a solute can be dissolved in a solvent. When a points reached where no more solute will dissolve, the solution is said to be saturated.
- 24What is miscible and immiscible?Polar - Polar = Miscible
Non-polar - non-polar = Miscible
Polar - Non-polar = Immiscible - 25Define PolarPolar as in poles, two poles of the globe therefore two charges
- Two distinct areas of charge across the molecule
- A molecule that contains a permanent dipole e.g. dispersion forces cannot change the area of charge, the + & - end of the dipole doesn't change - 26Define Non-polar- No distinct areas of charge across a molecule
- A molecule that does not contain a permanent dipole
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- Chemistry Stage 1 Flashcards on Topic 4.1 Miscibility and Solutions, created by Mabel G on 15/08/2018.
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