Matter may be classified into mixtures and pure substances. Give an example of a mixture and a pure substance you might encounter in your daily life, and explain how you would know which one is a mixture and which one is a pure substance.
How could you separate a mixture of sand and water?
Which metric unit would you choose to compare these three lengths: l1 = 0.5 mm, l2 = 0.00016 m , l3 = 6200 nm, l4 = 4.3 E-5 m? Convert the three lengths into your chosen units and order them from small to large.
You measured the volume of a sample 3 times and obtained the following results: 14.23 ml, 14.17 ml, 14.25 ml. Calculate the average volume and state it with the approprate number of significant figures.
You add 1.01 mg of NaCl (mNaCl) to 2.000 kg of water (mH2O). What is the mass mtotal of the resulting solution? In your answer, start with the quantity, show how you plan to calculate it, insert the appropriate values and use the appropriate number of significant figures in your result.
In the newspaper "The Onion", a new method of removing carbon dioxide from the atmosphere is described. The article claims that the chemical reaction used results in reactants that have less mass and less volume than the reactants. Comment, referring to basic laws of chemistry.
If you are given a sample of a pure substance for analysis, what properties would you measure to identify the substance (name two)? Are these extensive or intensive properties?
In the symbolic notation of the most common isotope of carbon, 12 / 6 / C, which number specifies the number of protons? How many neutrons does 12-carbon have? How many valence electrons does 12-carbon have, and how many in total?
Would two non-metals form an ionic or a covalent compound? Explain, using the location of non-metals and noble gases in the periodic table of elements.
Name and write the chemical formula of 4 cations and 4 anions, among them at least 2 polyatomic ions.
Fill in the elements C, F, Mg, N, Na, Ne, O into the empty boxes left in the periodic table.
If asked to determine the composition of a heterogenous mixture of NaCl (table salt) and sucrose (household sugar), what challenges do you have to surmount? How could you make your job easier?
If you know that Ag readily forms +1 cations, whereas Pt occurs in elemental form and is not very reactive, what properties would you expect of Pd? Explain
