S1-Chem-Solutions and Suspensions Flashcards
What is a mixture?
Mixtures are combinations of two or more substances which are not chemically combined together. Each substance retains their own chemical and physical properties.
What are the two main groups that mixtures can be classified into?
- Homogeneous
- Heterogeneous
What is a homogeneous mixture?
It is a mixture that has a uniform appearance and composition throughout.
Describe a homogenous mixture
- physical & chemical properties same in every part
- solutions
- components not distinguishable
What is a heterogeneous mixture?
It is a mixture that does not have the same appearance and composition throughout.
Describe a heterogeneous mixture
- physical & chemical properties not the same in every part
- visible different phases/physical states
- components are distinguishable
What is a solution?
A solution is a mixture consisting of particles of two or more substances that are distributed evenly throughout.
What is a solute?
It is a substance that is dissolved in another substance. Present in lesser quantity
What is a solvent?
It is a substance that dissolves another substance. Bulk of the solution, present in greater quantity
What is dissolving?
Process in which particles of substance separate and spread evenly throughout a mixture.
What is water known as?
Universal Solvent
What is an aqueous solution?
A solution in which the solvent is water.
Give characteristics of the aqueous solution. (3)
- cannot be filtered/ no residue left
- clear & transparent
- left to stand, no particles sink
Why is there no residue left when a solution is filtered?
- particles of solute small
- able to pass through pores of filter paper
Why is light able to pass through a solution?
- particles of solute small
- unable to block any light
What is a suspension?
A suspension is a mixture containing insoluble solid particles suspended in a medium such as air or water.
Characteristics of a suspension
- separated by filtration/ residue left
- does not allow light to pass through/ scatters light
- left to stand, particles sink to the bottom
Why are there residues left on the filter paper when a suspension is filtered?
- particles of solute too large
- unable to pass through pores of filter paper
Why is light unable to pass through suspension?
- particles of solute large
- block light
What is the definition of concentration of solutions?
It is a measure of the amount of solute dissolved in a given amount of solvent.
Formula of concentration of of a solution
Concentration = Mass of solute (g) / Volume of solvent (cm3)
What is solubility?
Solubility is the maximum amount of solute which can dissolve in 100g water at a fixed temperature.
What are the 3 factors that affect the solubility?
- type of solvent
- type of solute
- temperature
How does type of solvent affect the solubility?
ability to dissolve a given solute
How does type of solute affect the solubility?
- ability for a solute to dissolve in a given solvent
How does temperature affect solubility?
- effect of hotness and coldness of a solvent
What is a solubility curve?
A graph that shows the maximum amount of a solute that can dissolve in 100g water at a given temperature to form a saturated solution.
What is the def of rate of dissolving of substances?
It is a measure of how fast a solute dissolves in a fixed amount of a solvent completely.
What are the factors of rate of dissolving of substances?
- stirring effect
- amount of solvent
- particle size
- temperature
Effect of factors of rate of dissolving substances
- stirring : increase increase
- amount of solvent : increase increase
- particle size : decrease increase
- temperature : increase increase
