Lab+3+ +physical+and+chemical+properties

Lab 3 - Physical and Chemical Properties of Elements Timeline: 2 classes Introduction : By this time you are expected to be able to draw the Bohr-Rutherford diagram upto calcium and use the diagram to predict the number and arrangement of outermost electrons. Similarly, you should also be able to use your diagram to predict the electron configuration [using the 2,8,8 or s,p,d,f method]. By examining the electron configuration we can gain insight into some periodic properties of the table of the periodic table. Physical properties tend to fall into three categories: properties of metals, properties of semi-metals [metalloids] and properties of the non-metals. Task 1 - Physical properties and changes Your first task is composed of a number of sections. The first builds on previous knowledge. You should have a general idea of some physical properties. However, I want you to go beyond what you know and find other physical properties you are not -o r less- familiar with. Do some quick research and find other, easily measurable properties you can investigate in class. Secondly, using any available equipment [with the teachers permission] collect data as to which elements and compounds have the physical properties you know or have learned. Create a data table in your wiki pages to record and organize your results. Summary: Time budget background research on physical properties [h omewor k/ver y smal l cl ass ti me] gather qualitative physical evidence on the substances provided [i n cl ass] record and organize your data [i n cl ass an d h omewor k] conclude with general classification of substances into categories [metal, non-metal, metalloid, ionic, covalent] I KNOW!, but research the ionic and covalent anyway!

Task 2 - C hemical properties and changes Similarly, you have some previous knowledge of chemical properties. Once again, I want you to go beyond this knowledge and investigate other chemical properties. Many of these we will not be able to directly investigate to collect evidence. There are some very basic but informative properties we CAN investigate. Lastly, I want you to research a nd find the splint tests that allow us to differentiate between H 2 , O 2 and CO 2 gases. When you do a few of these tests you should collect the gas and test for the different gases. use pH paper to test the water pH after the reaction. [You can do this for the acids if you think you'll see a change] use a thermometer to test for temperature changes For the following table, describe the level of reaction on a scale of 1 to 5 . One can describe very little reaction, five very reactive. the HCl(aq) is 2M and 6M. You will learn what the M refers to soon enough. In many of the combinations below it will not be possible to collect the gas easily o r safely therfore we will predict the gas produced using the following common types of reactions. Use these common reaction types to predict the gas produced [if any] metals and acid react to form a salt [an ionic compound] and hydrogen gas. metal

acid

salt

hydrogen gas

Mg (s) + HCl (aq) ↔ MgCl2 (aq) + H2 (g) some metals and water [i f th e metal i s r eacti ve en ou gh ] react to form hydroxide and hydrogen gas metal water hydroxide hydrogen gas Li(s) + H2 O (l) ↔ LiOH(aq) + H2 (g) carbonate salts and acid react to form an ionic salt, water and carbon dioxide gas carbonate salt acid salt water carbon dioxide Na 2 CO 3 (s) + HCl (aq) ↔ NaCl (aq) + H2 O (l) + CO 2 (g) Attempt to classify the elements in terms of their reactivity

Results: Table 1 - Qualitative evidence for chemical changes/reactions. Element

cold hot dilute water water HC l

[HC l](aq)

**gas C onduct Temp. produced electricity change

(aq) Lithiu m

dem o‡

dem o ‡

n/a

n/a

Sodiu m

dem o ‡

dem o ‡

n/a

n/a

Potassiu m

dem o ‡

dem o ‡

n/a

n/a

Magnesiu m

*ch eck

Calciu m Alu minu m Copper Zinc Iron Lead Carbon Su lpher Calciu m carbonate

*ch eck

**th e gas pr odu ced can be tested u si n g a spl i n t test. ‡du e to th e r eacti vi ty ...i ts dan ger ou s. CO2 gas wi l l exti n gu i sh a bu r n i n g spl i n t H 2 gas wi l l ' pop' wh en l i t by a bu r n i n g spl i n t O2 gas wi l l r ei gn i te a gl owi n g, exti n gu i sh ed spl i n t.

pH Test