The Chemical Earth Flashcards
Define homogenous.
Homogenous means of uniform composition throughout. The properties and composition of a homogenous mixture are the same throughout the mixture. For example pure water, sugar, aluminium, petrol or whisky.
Define heterogenous.
Heterogenous are not uniformly mixed throughout the mixture. Where we can recognise small pieces of the material which are different from other pieces. E.g. Strawberry jam, oil, water, or wood.
In all chemical reactions, mass is conserved. The total mass of all the reactants equals the total mass of all the products. What is this law called?
Law of Conservation of Mass (or matter)
Define mixture.
Consists of two or more different elements and/ or compounds physically intermingled.
Can be separated into its components by physical means.
Has the constituents that retain their original properties.
Thus, it’s an impure substance.
Define element.
Consists of only one type of atom, cannot be broken down into a simpler type of matter by either chemical or physical means and cannot exist as either atoms or molecules.
Define the biosphere, and give examples of mixtures of elements and compounds.
The biosphere consists of the atmosphere, lithosphere and hydrosphere. Where mixtures include, air, land, surface rocks and water.
Define lithosphere and give examples of mixtures and compounds in that type of sphere.
The lithosphere is the solid outermost shell of Earth, i.e. The crust and the upper art of the mantle. It contains various mixtures such as, rocks that contain silicates, sand, soil, mineral ores, coal, oil and natural gas.
Define hydrosphere and give examples of mixtures in that sphere.
The hydrosphere includes all water on Earth. About 71% of the Earth is covered by water. As water is the universal solvent and the basis of all life on Earth. E.g. Are salt water, water, fresh water.
Define atmosphere and give examples of mixtures.
The atmosphere is composed of gases. 78% nitrogen, 21% oxygen and 1% mixture of minor gases (mainly argon).
Define inorganic compounds.
Inorganic compounds are those compounds containing elements other than carbon.
What is the Goldilocks principle?
Earth has the right mass, the right chemical composition, the right atmosphere, and is the right distance from the Sun . Not too much, not too little.
Define suspension.
A liquid with insoluble material suspended in it.
Name all types of procedures that can be used to separate mixtures.
Filtration Separating funnel
Fractional Distillation Distillation
Centrifuging Froth Floatations
Crystallisation
What is gravimetric analysis?
Gravimetric analysis of a mixture is a technique that allows us to find out the composition of the mixture by separating out the components and weighing them.
What is the product of metal + acid -> ?
Salt + Hydrogen
E.g.
Magnesium + Hydrochloric acid -> Magnesium chloride + hydrogen
Mg(s) + HCl (l) -> MgCl2 (aq) + H2 (g)
