Name: ______Date: ______SNC 1D Chemistry Unit Review

For a list of the topics you are responsible for, see the Chemistry Learning Goals and Success Criteria sheet. In addition, include that you need to have the understanding of independent, dependent, and controlled variables for scientific experiments.

Practice Questions

1) Go to HCtoday.ca.  Academics  Teacher Pages  K.Waller  SCIENCE SNC1D  SNC1D Notes Spring 2014  1-Chemistry  Day x- Chemistry Practice Multiple Choice 2) Describe the following models of the atom: Dalton, Thompson, Rutherford, and Bohr. Also specify what each scientist contributed to the model. Dalton - atoms are small indestructible spheres of matter like billard balls -discovered atoms of different elements are different Thompson - atoms have a positively charge ‘dough’ with electrons placed throughout like raisins in plum pudding -discovered charge in the atom Rutherford -atoms are mostly empty space (where electrons are) with a dense positive centre (nucleus) -used the gold foil experiment to discover the nucleus; most particles went through, few bounced back Bohr -atoms have a dense nucleus surround by shells (energy levels) of electrons -discovered electrons with certain energy jump from one shell to another 3) Describe the location, mass, and charge of an electron, neutron, and proton.

4) Give the group number (and name if known), atomic mass, atomic number, symbol, and state if it is a metal or non-metal for the following elements: cesium, silicon, argon, bromine Element Atomic mass Atomic number Symbol Metal/ Non-metal Cesium 132.9 55 Cs Metal Silicon 28.09 14 Si Metalloid Argon 39.95 18 Ar Non-metal Bromine 79.90 35 Br Non-metal

5) Fill in the following table.. Symbol Element name Atomic Atomic # of # of # of Solid, number mass protons neutrons electron liquid s or gas K potassium 19 39.10 19 39-19=20 19 s Be beryllium 4 9 4 9-4=5 4 s S sulfur 16 32.07 16 32-16=16 16 s Br bromine 35 79.90 35 80-35=45 35 l O oxygen 8 16.00 8 16-8=8 8 g Li Lithium 3 6.94 3 7-3=4 3 s O oxygen 8 16.00 8 16-8=8 8 g

6) Draw the Bohr-Rutherford diagrams of Be, Si, and O. Beryllium Silicon

Oxygen

7) Describe the pattern of electron arrangement across a period and down a group. Across a period- one valence electron is added as you move from left to right Down a group- one shell is added as you go down each group, but the number of valence electrons remains the same

8) What is the trend in reactivity of the alkali metals (which is the most reactive, the least)? As you go down the alkali metal group the elements get more reactive. 9) Explain the underlying reason for the trend. This trend occurs because as you go down the group the number of shells increases, increasing the distance between the positive nucleus and the single valence electron. As the valence electron and the nucleus get further apart the attraction between them decreases making the valence electron easier to remove (more reactive). 10) Describe the five components of the particle theory of matter.

11) What is the difference between an element and a compound? Compounds contain two or more different elements bonded together. Elements are composed of one type of atom. Elements can exist as atoms or molecules.

12) What is the difference between an atom and a molecule? An atom is the smallest component of an element having the same properties as the element. A molecule is formed when two or more atoms are bonded together. 13) What is the difference between a pure substance and a mixture? Pure substances have only one kind of atom or molecule. A mixture has more than one type of pure substance mixed together.

14) For each of the following state which of the following words apply (atom, molecule, element compound, pure substance, mixture). Explain why they apply:

a) lemonade b) carbon c) H2 gas d) NaCl (table salt) f) air h) chalk (CaCO3)

e) Fe g) C6H12O6

lemonade mixture Carbon Atoms of an element, pure substance

H2 gas Molecules of an element, pure substance NaCl Compound, pure substance Fe Atoms of an element, pure substance Air Mixture of atoms and molecules

C6H12O6 Compound, pure substance chalk Compound, pure substance

8) For the following compounds state which atoms are present and how many for each:

i) Na2SO4 ii) C2H4 iii) CoCl2 iv) CaCO3

Na2SO4 2 sodium 1 sulfur 4 oxygen

C2H4 2 carbon 4 hydrogen

CoCl2 1 cobalt 2 chlorine

CaCO3 1 calcium 1 carbon 3 oxygen

9) Define the terms physical and chemical property. 10) What are 8 physical properties that can used to describe matter.

11) What is the difference between lustre, malleability, and ductility? Lustre describes how easily light is reflected off a substance, malleability describes the ability of a substance to be hammered into sheets, and ductility describes a solid’s ability to be stretched into a wire. 12) Give three qualitative and three quantitative properties of your pencil. Qualitative- solid, opaque graphite centre is dark grey, slightly lusterous and conducts electricity. Quantitative- 7 cm in length, 5 mm diameter, graphie has a density of 2.09g/cm3 13) Give three physical and one chemical property of gasoline. Physical- transparent, yellow, non-viscous liquid Chemical- combusts easily 14) What are the three density formulas? D=m/V V=m/D m=DV 15) What are two possible units for density? g/mL g/cm3 kg/L 16) What is the formula for the volume of a rectangular block? V= length x width x height 17) Use the GRASP method to solve for the following. a) The mass of a regulation golf ball is 45.9 g. If it’s volume if 38.8 mL, what is its density? Will it sink or float? Explain why. Given m = 45.9 g V = 38.8 mL

Required D= ?

Analysis Find the density using D = m/V then compare it to the density of water (1 g/mL). If the density is greater than it will sink, if it is less, the golf ball will float.

Solution D = m = 45.9 g = 1.18 g/mL V 38.8 mL

Summary The density of the golf ball is 1.18 g/mL which is higher than the density of water so the golf ball will sink when put in water.

b) A block of wood has a density of 0.89 g/cm3. If its length, width, and height are 8.9 cm, 3.4 cm, and 2.3 cm, respectively, what is its mass? Given l= 8.9 cm w= 3.4 cm h= 2.3 cm D= 0.89 g/cm3 Required m=? Analysis Find the volume of the block of wood using V=lxwxh then use m=DV to find the mass Solution V= l x w x h = 8.9 cm x 3.4 cm x 2.3 cm = 70 cm3 m = DV = (0.089g/cm3)( 70 cm3) = 6.19 g Summary The mass of the block of wood was 6.19 g.

20) A gas is tested to be either hydrogen, oxygen, or carbon dioxide. What evidence would you look for to identify which of the three it may be? Hydrogen- burning splint gives a ‘pop’ sound Oxygen- glowing splint is reignited Carbon Dioxide- burning splint or candle is smothered (flame goes out)

21) A student runs an experiment testing the effect of different amounts of salt on the boiling point temperature of water. In pot A she adds no salt (NaCl) to the water, in pot B she adds 20 g of NaCl, and in pot C she adds 40 g of NaCl. She boils each and finds that pot A boiled at 100 °C, pot B boiled at 102 °C, and pot C boiled at 104 °C. Identify the dependant variable, the independent variable, and 2 controlled variables. Independent variable- amount of salt is changed Dependent variable- boiling point temperature is measured Controlled variables- the type of salt (NaCl), the size of the pot, the amount of water, the type of pot, the stove element and temperature etc. should all be kept constant