Conservation of Mass Due Monday 5th December at Lunch Time

Task Two

Today you’ll be aiming for your Lomonosov badges if you do not yet have it.

This link is for practice.

http://www.sciencegeek.net/APchemistry/APtaters/EquationBalancing.htm

Solve any five of these an put them on your student journal to achieve Lomonsov:

1.            C₃H₈    +    O₂    g      CO₂      +     H₂O
2.           Al₂(SO₃)₃   +   NaOH  g   Na₂SO₃    +   Al(OH)₃
3.           Al₂O₃    +   Fe  g   Fe₃O₄    +     Al
4.            KClO₃   g   KCl   +  O₂
5.            NH₄NO₃  g    N₂O    +    H₂O
6.            NaHCO₃   g   Na₂CO₃   +    H₂O    +   CO₂
7.            P₄O₁₀     +    H₂O  g     H₃PO₄
8.            Al    +    H₂SO₄    g     Al₂(SO₄)₃     +    H₂
9.            Be₂C   +    H₂O   g    Be(OH)₂     +   CH₄
10.***     S    +   HNO₃   g    H₂SO₄   +    NO₂   +   H₂O
11.            NH₃   +   CuO  g    Cu   +   N₂   +   H₂O
12.***      Cu   +    HNO₃   g   Cu(NO₃)₂    +   NO   +    H₂O

Task Two

Conservation of mass: Quote the conservation of mass law

Task Three

Complete a short history of the periodic table

A GCSE level piece would answer all of these questions. Give it a go! All the answers are in the links below.

Start with Lavoisier

Antoine Lavoisier’s 1789 classification

* (a) Define what we mean by (i) an element, (ii) a compound.

* (b) Name two ‘substances’ in the list which are NOT an element, compound or mixture.

* (c) Is Lavoisier correct to refer to charcoal as an ‘element’?

* (d) Why are sulphur, phosphorus and charcoal described as ‘acid-making’ elements?

* (e) Are all the metallic ‘elements’ he listed really elements?

* (f) Did he genuinely distinguish between metallic and non-metallic elements?

* (g) Which substances in his list, from your own modern knowledge, are definitely compounds?

* (h) Why do you think he thought your answers to (g) were elements?
Now focus on on the 1829 work of Johann Döbereiner

* Johann Döbereiner noted that certain elements seemed to occur as ‘triads’ of similar elements eg

* (i) lithium, sodium and potassium

* (ii) calcium, strontium and barium

* (iii) chlorine, bromine and iodine

* (a) Although the lists are incomplete, what do we now call these ‘collections’ of similar elements in a modern periodic table? (his triads where the forerunner of this ‘idea’)

* (b) What are the modern names for these three ‘collections’?
Now focus on John Newlands 1864

(every 7 elements, the 8th seemed to be very similar to the 1st of the previous 7)

Newlands’ Octaves

* Note: Di in column 6 was a mixture of elements, Ro is now Rh rhodium.

* (a) In which ways is Newlands ‘Periodic Table’ superior to Lavoisier’s classification of the elements?

* (b) Why is Newlands classification superior to Johann Döbereiner’s work?

* (c) Can you spot any ‘Groups’ of elements which you find on a modern Periodic Table? and are they classified in their own right an not mixed up with elements from other ‘modern’ groups or series?

* (d) From your own knowledge, can you spot ‘groups’ of elements which seem very out of place compared to a modern Periodic Table?

* (e) Can you spot a metallic and non-metallic element correctly placed in the same vertical column group?

* (f) Newlands contributed to two important ideas about the structure of the modern periodic table, what are they? (take a ‘broad’ view and think of Johann Döbereiner’s work too).
Now focus on Dmitri Mendeleev’s Periodic Table of 1869

(It was published simultaneously in 1869 with the work of Lothar Meyer who looked at the physical properties of all known elements. He noted ‘periodic’ trend patterns eg peaks and troughs when melting or boiling points and specific heat values were plotted against ‘atomic weight’ – what  we now call relative atomic mass)
* (a) In what order did Mendeleev originally set out the elements?

* (b) Which group of elements is missing? can you suggest reasons for their absence?

* (c) Which element would be above Y (yttrium) in Group III,  below aluminium in Group III? and which element would be below silicon in group IV?

* (d) Mendeleev predicted the existence of the elements for the answers to (c) and predicted their properties and for some of their compounds eg their formula and physical and chemical character.

* (i) How could you do this in principle?

* (ii) What type of elements might they be?

* (iii) Can you predict the formula of their oxide and chloride?

* (e) State as many features as you can spot, in which Mendeleev’s Periodic Table is superior to Newlands ‘classification’
Now focus on a typical modern version of the Periodic Table

* (a) In which order are the elements set out in the modern periodic table?

* (b) The pairs of elements: (i) tellurium (Te, atomic mass 127.6) and iodine (I, atomic mass 126.9), AND (ii) argon (atomic mass 39.95) and potassium (atomic mass 39.10), do not follow the ‘historic rule’ quoted in Q4(a). Explain why not?

* (c) It was in 1914 that a scientist called Moseley put tellurium and iodine in their correct ‘periodic order’, so what piece of information did he know that Mendeleev didn’t?

* (d) State as many features as you can think of, in which the Periodic Table is superior to Mendeleev’s Periodic Table.

* (e) Where have elements 104-109 come from?

* (f) The scientist called Glenn Seaborg is rarely known by any school student, at least compared to Mendeleev. Find out what areas of science he worked in and is it science of the future?
http://www.docbrown.info/page03/3_34ptable.htm

http://www.rsc.org/education/teachers/resources/periodictable/pre16/develop/mendeleev.htm

That will help!