#05-Shin Yoong
Her answers are very well explained and the way the answers are displayed clearly(easy to see).I can also see that she made the effort in changing the font size of the numbers in the chemical equations,which could be tremendously troublesome.I also found her answers very detailed,getting to the point of the question quickly.Moreover,I could find very little error in the answers.The blog is also very organised and nice,living up to its name"...Relaxing...".
#27-Aleen         
The answers given were very detailed and did not stray from the question.There is also a good discrimination between the questions and answers given which makes it easier to read.However,there is a difference in the questions' font which makes it a bit unappealing but does not affect the quality of the answer which is superb.I can see her make the effort to change the font size for the chemical equations which I will say again,is a pain to do.The design of the blog is also nice,simple.
#36-Jia Le         
His answers are very well displayed(easy to see)and very reader-friendly.Aside from the appearance of the answers,the quality of the answers also impressed me,in their deep detail and clear organisation of the answers.I can find very little mistakes or error in his answering and it can be safe to say that his blog is truly the easiest one I found to read.The design of his blog is a true accompaniment to its title"Plain & Simple" and also a true accompaniment to his facination with K-pop.Truth be told,I really enjoyed listening to the K-pop music while on his blog.

Q1 Zinc nitrate reacts with aqueous ammonia (NH4OH) to form a salt and a base. 
(i) Name the salt and the base.
Ans:The salt is Zinc hydroxide.The base is Ammonium nitrate.
(ii) Describe the observations for the reaction.
Ans:A white precipitate is formed when the two aqueous solutions(Zinc nitrate and aqueous ammonia)are introduced to each other.
(iii) Write a chemical equation for the reaction (include state symbols).
Ans:ZnNO3(aq)+NH4OH(aq)-->ZnOH(s)+NH4NO3(aq)
(iv) Write an ionic equation for the reaction. 
Ans: Zn(+)(aq)+OH(-)(aq)-->ZnOH(s)

Q2 Ammonium sulfate is heated with sodium hydroxide.
(i) Write a chemical equation (include state symbols) for the reaction. 
Ans: (NH4)2SO4(aq)+2NaOH(aq)-->Na2SO4(aq)+2H2O(l)+2NH3(g)
(ii)  Describe a test for the gas.
Ans:Hold a piece of damp red litmus paper above the solutions reacting.


Q3 An unknown green solution is heated with a piece of aluminium foil and sodium hydroxide solution. 
(i) The gas produced turns damp red litmus paper blue.  Name the gas evolved.
Ans:Ammonia
(ii) This is a confirmatory test for an anion.  Name this anion. 
Ans:Nitrate
(iii) Give a possible cation which gives the green solution.
Ans:Iron(III)


Q4 Sulfuric acid is titrated with potassium hydroxide in the preparation of potassium sulfate salt. 
(i) Explain why this method is recommended for the preparation for this salt. 
Ans:The salt produced is soluble and in Group(I),which is the type of salt that is produced through titration.
(ii) Write an ionic equation for the reaction.
Ans:H(+)(aq)+OH(-)(aq)-->H2O(l)

Q5 Excess zinc carbonate is added to hydrochloric acid in the preparation of zinc chloride salt.
(i) Write an ionic equation for the reaction.
Ans:ZnCO3(s)+H(+)(aq)-->Zn(+)(aq)+H2O(l)+CO2(g)
(ii)  Why excess zinc carbonate is used?
Ans:To ensure the complete reaction of the hydrochloric acid with the zinc carbonate.
(iii) Briefly explain how the zinc chloride crystals can be obtained.
Ans:After the reaction of the zinc carbonate with the hydrochloric acid,filter and heat the filtrate until there is a small amount of water for crystalization.

Chemistry Assignment 1

1. What does an atom looks like?  What are the sub-atomic particles inside it.....(talk about electrons, neutrons, protons, electron shells, nucleus....)
Ans:An atom is composed of a nucleus which contains both protons,which are of +1 charge,and neutrons,which have no charge.An atom is also surrounded by electron shells containing up to 8 electrons,which are of -1 charge.

2. Draw the atomic structure of a sodium atom and a sodium ion....explain why you draw it this way.
Ans:

The sodium atom is drawn according to how many electrons it has,while the sodium ionhad to lose one of its electrons to complete its valence shell and become stable.

Picture from:http://www.google.com.sg/imgres?imgurl=http://www.bbc.co.uk/schools/gcsebitesize/science/images/diag_sodium.gif&imgrefurl=http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa/atomic/ionicrev2.shtml&usg=__9X8Y1Q3T4Y1OCZmkxlYMLrulW0I=&h=135&w=232&sz=5&hl=en&start=15&sig2=mETXZFzYxiRv_K2a4rXoxg&zoom=1&tbnid=ej3WGIdtzk7kBM:&tbnh=86&tbnw=148&ei=EbYPTrKbE9DrrQeds7CHBA&prev=/search%3Fq%3Dsodium%2Batom%26hl%3Den%26biw%3D1024%26bih%3D556%26gbv%3D2%26tbm%3Disch&itbs=1&iact=hc&vpx=164&vpy=239&dur=62&hovh=108&hovw=185&tx=51&ty=59&page=2&ndsp=15&ved=1t:429,r:10,s:15&biw=1024&bih=556

3. Draw the atomic structure of a sulfur atom and a sulfide ion....explain why you draw it this way.

Ans:

The sulfur atom is drawn according to the number of electrons it has,while the sulfide ion is an atom which gains 2 electrons to achieve stability and a complete valence shell.

Pictures from:http://www.google.com.sg/imgres?imgurl=http://www.micromountain.com/sci_diagrams/at_struct/at_struct_assets/sulphur_lab_usa.jpg&imgrefurl=http://www.micromountain.com/sci_diagrams/at_struct/at_struct_pages/sulphur_lab_usa.htm&usg=__fh2IOpVcz2ubaz4ETf7d3UchFDk=&h=560&w=360&sz=29&hl=en&start=0&sig2=JcDLhvgdUxp8rzV0OIYVgg&zoom=1&tbnid=ZVxkffioyIMwCM:&tbnh=138&tbnw=105&ei=07kPTuyUE87MrQeHz-CHBA&prev=/search%3Fq%3Dsulfur%2Batom%2Bstructure%26hl%3Den%26biw%3D1024%26bih%3D556%26gbv%3D2%26tbm%3Disch&itbs=1&iact=hc&vpx=145&vpy=165&dur=172&hovh=280&hovw=180&tx=106&ty=148&page=1&ndsp=15&ved=1t:429,r:5,s:0&biw=1024&bih=556

http://www.google.com.sg/imgres?imgurl=http://course1.winona.edu/sberg/ILLUST/Sulfur.gif&imgrefurl=http://course1.winona.edu/sberg/241f08/Lec-note/Chem-1.htm&usg=__gJA6ioW4SK5QIl6t3TDrSKyXBIA=&h=221&w=880&sz=14&hl=en&start=25&sig2=I7dOVOYEL65txXJTUnEvag&zoom=1&tbnid=d3J7UYckxKJOpM:&tbnh=40&tbnw=161&ei=QrsPTre7FovzrQe-_fiHBA&prev=/search%3Fq%3Dsulfur%2Bion%2Bstructure%26hl%3Den%26biw%3D1024%26bih%3D556%26gbv%3D2%26tbm%3Disch&itbs=1&iact=rc&dur=672&page=3&ndsp=15&ved=1t:429,r:6,s:25&tx=127&ty=17

4. Chlorine-35 atom and Chlorine-37 atom are called isotopes...Use these two examples to explain what is 'isotopes'.

Ans:Isotopes are different atoms of the same element which have the same number of protons but different numbers of neutrons.Thus,they have the same proton number,in the case of chlorine
,17,and different mass numbers,in the case of chlorine,35 and 37.

5. Sodium is a metal and sulfur is a non-metal....why we classify them this way??
Ans:Sodium is a metal as it is in the group(I) and sulfur is a non-metal as it is in group (VI).Metals are generally in the groups(I),(II),(III) while non-metals are generally in the groups(IV),(V),(VI),(VII),(VIII).