Chemistry Flashcards
What is a dependant variable, independent variable and a controlled variable?
A dependent is a variable that is expected to change when the independent variable is changed. The dependent variable is observed or measured during the experiment. A independent variable is the variable that the scientist changes to observe its effect on another variable A controlled variable is the conditions that must be kept the same throughout the experiment.
What is a saturated solution?
A solution that can not dissolve any more solute.
What is a solvent?
A solvent is the substance that things get dissolved into.
What is a solute?
Thing that gets dissolved.
Why can blood be centrifuged but sea water can not?
Sea waters salt is dissolved whereas blood has insoluble components.
What is chromatography?
A separation technique that separates small traces of substances using differences in solubility. Eg: Paper chromatography.
What is a pure substance?
Pure substances matter composed entirely of one type of atom or molecule.
A suspension is what?
Particles that float around in suspension in the solvent.
Define the terms colloid and emulsion.
colloid a mixture in which extremely small particles of one substance are spread evenly throughout another substance
emulsion a colloid with droplets of one liquid spread evenly through another
Describe distillation and crystallisation.
A separation technique that uses evaporation to separate substances. The mixture is heated so that one substance evaporates. The vapour is collected and condenses into a liquid. Eg: Salt water distillation. Crystallisation formation of ordered patterns of particles due to the attraction between particles.
What are things you need in a science prac report?
Title, Aim, Introduction, Hypothesis, Method, Diagrams (if used), Results, Discussion (VERY IMPORTANT), Conclusion.
