Introduction to Chemistry of Mixtures Worksheet 4

Worksheet 4. Introduction to Chemistry of Mixtures 1. Chemical structures 1.1 Draw the chemical structure of the following diatomic molecules (including lone pairs), and write their state of matter at room temperature as (S), (L) or (G) for solid, liquid or gas. 1. H2. 2. N2. 3. O2. Oxygen is a gas at room temp. 4. F2 Florine is a gas at room temp. 5. Br2 Hydrogen is a gas at room temp. Nitrogen is a gas at room temp. Bromine is a liquid at room temp. 1.2 Molecular structures of common molecules (include lone pairs in your drawings) H2O CO2 Chemical names: Dihydrogen monoxide Carbon Dioxide Draw the following structures: Methane Ethane Propane Draw the following structures on your own and correct them: Butane Pe ane Hexane Heptane Octane Nonane Decane Draw the line diagram for ethanol: Draw the line diagram for pentane C2H5OH Find the chemical formula of this molecule: C8H9NO2 2. Classification of matter 2.1 Fill in the Blanks A(n) element is a pure substance that is made of only one kind of atom. A(n) compound is a pure substance containing two or more elements that are chemically combined. A(n) Mixture is made of two or more substances that are physically combined. A(n) mixture that is uniformly mixed is called homogeneous. A(n) mixture that is not uniformly mixed is called heterogeneous. The water must be evaporated using heat in order to separate it from the salt. How can we separate ethanol and water? Using distillation, the ethanol will evaporate first and the condensation of the ethanol can be collected through this process due to the different boiling points of the two substances. How can we separate salt and sand? Add to water and filtrating the sand and salt mixture then washing to separate. The process of separating salt and sand is called filtration. Filtration can be achieved by using water to dissolve the salt and leave behind the sand then the substance can be filtered and the water that has dissolved the salt (filtrate) will collect at the bottom of the funnel and the sand (residue) will remain in the paper filter. What is a separator funnel? Used to separate immiscible liquids like oil and water, draining the water from the bottom due to the water’s heavier density and turning it off using the stop cock before it gets to the oil which has a lighter density.