Q5 Excess zinc carbonate is added to hydrochloric acid in the preparation of zinc chloride salt.

(i)
               
(ii) Excess Zinc carbonate is used to make sure that all the hydrochloric acid are completely neutralised.

(iii) Firstly, fliter out the excess zinc carbonate from the solution and the zinc chloride solution will be left.Zince chloride crystals can be obtained by evaporating the Zinc chloride salution to saturated and allow the sartuated zinc chloride solution to cool down. Crystals of zinc chloride will be formed.

Q4 Sulfuric acid is titrated with potassium hydroxide in the preparation of potassium sulfate salt.

(i) Potassium sulfate is a Group(I) soluble salt. Titration is recommended for preparation of all Group (I) salts as they are soluble. As the solutions used are colourless, indicatior is also used to identify the end point of neutralization between sulfuric acid (colourless) and potassium hydroxide (colourless) where the solution with indicator turns colourless.

(ii)
   

Q3 An unknown green solution is heated with a piece of aluminium foil and sodium hydroxide solution.

(i) The gas produced is Ammonia.

(ii) Anion: Nitrate ions (NO3-).

(iii) Cation: Iron (II) (Fe2+)

Q2 Ammonium sulfate is heated with sodium hydroxide

2(i) (NH4)2SO4 (aq) + 2NaOH (aq) --> Na2SO4 (aq) + 2NH3 (g)+ 2H2O (l)

(ii) Ammonia produced will turn damp red litmus paper to blue.

Prepare for EYE : 5 Questions on Ionic Equations, Colours of Cations & Anions, Acids, Bases, Alkalis, Salts

Q1.(i) Zinc Nitrate+Aqueous ammonia --> Zinc hydroxide + Ammonium Nitrate
Thus, the salt formed is ammonium nitrate while the base for is zinc hydroxide.

(ii) Observation of reaction: When Ammonium hydroxide(colourless solution) is added to Zinc nitrate(also colourless solution), white precipitates formed as Zinc Hydroxide is insoluble.

(iii)   Zn(NO3)2 (aq) + 2NH4OH (aq) --> Zn(OH)2 (s)+ 2NH4NO3 (aq)

 (iv)
    

Comments on my fellow friends' blogs

Yiting,http://yhss-3e5-chemistry-29-2011.blogspot.com/ is one-of-a-kind as she actually drew out the drawings and I could see the effort and the heart that she put into this Chemistry project given by Mr.Tan. However, she can improve her sentence structure and construct clearer sentences which may be more interesting and clearer for the people to read through. After all, it is still a nice blog which could capture my attention.

Aleen, http://yhss-3e5-chemistry-27-2011.blogspot.com/ also has a nice blog which is well- rounded and suitable decoration for a chemistry blog. Her answers were detailed and nothing particular in mistake. Nevertheless, again, if would have been better if she could make the posts clearer/easier to read and draw out most of the things that is she can. In addition, I do not regret checking her blog as it makes me realise the things that I have not included.

ChunBoon, http://3e5-chemistry-39-2011.blogspot.com/ has summarised answers which is
comprehensive for quick-revision. Nonetheless, it would have been better if he could eleborate a bit more on the answers. Still, it is considered pretty good as we have not actually learnt much on that chapter, particularly on the memorizing theory part. By the way, the blog theme is quite simple but still nice. :)

Picture taken from: http://www.google.com.sg/imgres?imgurl=http://www.watton.org/clipart/party/party109.gif&imgrefurl=http://www.watton.org/clipart/party/party.shtml&usg=__RUOLIiXIt2-4CUDwGoxM_eKdRHw=&h=283&w=520&sz=8&hl=en&start=0&sig2=M0SCJ_LZXcYXd1p-HyoeFw&zoom=1&tbnid=2FO0dTuz-CiuvM:&tbnh=89&tbnw=164&ei=PfQWToidBszsrQeU0_XPAQ&prev=/search%3Fq%3Dparty%26um%3D1%26hl%3Den%26sa%3DN%26rlz%3D1R2WZPC_enSG388%26biw%3D1600%26bih%3D702%26tbm%3Disch&um=1&itbs=1&iact=hc&vpx=765&vpy=68&dur=580&hovh=165&hovw=304&tx=163&ty=63&page=1&ndsp=36&ved=1t:429,r:13,s:0&biw=1600&bih=702

Chemistry Project: Question 5

In a periodic table, atoms which can form Positive ions are classified as metals while the atoms which can form Negative ions are classified as Non-metals.

 Sodium has the electronic structure of (2.8.1) and it has one valance electron. Thus, instead of getting seven more electrons, it loses its one valence electron to achieve stability. It has became positively charged ion as it had lost one valence electron in outer-most shell. Hence, it became Sodium (Na+) ion.

Sulfur on the other hand, it has electronic structure of (2.8.6) and it has two valence electrons. In addition, it gains two valence electrons to achieve stability. It has became negatively charged ion as it had gained two valence electrons in the outer-most shell.
Thus, it became sulfide (S 2-) ion.

Reference: http://www.google.com.sg/imgres?imgurl=http://www.supersonictubevehicle.com/images/cnt_per.jpg&imgrefurl=http://www.supersonictubevehicle.com/hytut.html&usg=__a0LboGnDickFXQtmBnIIPvoLZnk=&h=433&w=630&sz=102&hl=en&start=124&sig2=cpz5bjxbcWcp7Jq9QsOHDA&zoom=1&tbnid=qgUe_9M0z3ypsM:&tbnh=116&tbnw=169&ei=_psRTreJJceHrAfjoc2HBA&prev=/search%3Fq%3Dmetals%2Band%2Bnonmetals%2Bon%2Ba%2Bperiodic%2Btable%26um%3D1%26hl%3Den%26sa%3DN%26rlz%3D1R2WZPC_enSG388%26biw%3D1600%26bih%3D702%26tbm%3Disch&um=1&itbs=1&iact=hc&vpx=668&vpy=321&dur=166&hovh=186&hovw=271&tx=188&ty=110&page=5&ndsp=32&ved=1t:429,r:3,s:124&biw=1600&bih=702

Chemistry Project: Question 4

                                                   Chlorine 35

Chlorine 37

Definition of Isotope: Atoms of same element with same number of protons but different number of neutrons. 

Chlorine 35 is an isotope which has 17 Protons and 18 Neutrons. In contrary, Chlorine 37 has 17 Protons and 20 Neutrons. In conclusion, they are considered as isotopes since isotopes are atoms of same element with same number of protons but different number of neutrons. 

Chemistry Project: Question 3

               Sulfur Atom

Sulfur Atom has electronic structure of (2.8.6) and it has in total three shells. 

         Sulfide Ion
 

For Sulfide (S 2-) , it has electronic structure of (2.8.8) and it has gained 2 valence electrons in the valence shell as it takes in two valence electron to achieve stability. Therefore, Sulfur atom became Sulfur Ion as it gained two valence electrons.

Chemistry Project:Question2

               Sodium Atom

Sodium Atom has electronic structure of (2.8.1) and it has three shells.  

Sodium Ion

For Sodium ion (Na+), it has electronic structure of (2.8) and it has lost the valence shell as it gave away the valence electron to achieve stability. Thus, Sodium atom became Sodium Ion as it lost its valence electron.

Chemistry Project Question 1

Diagram of an atom

There are numerous atoms around the world, around us and even our bodies are made up of atoms. Each atom consists of main sub-atomic elements called "Electrons","Protons" and "Nutrons".

Protons and Neutrons are inside the nucleus shell whereas the Electrons are revolving around the nucleus in its own electron shell. Protons are positively charged (+) whereby the Electrons are negatively charged (-) . Nonetheless, Neutrons have zero charge and they are neutral as the name given. The outer-most electron shell of an atom is called as "valenced shell" and the valency of the atom depends on the number of electrons in the outer-most shell.

In every atom, the first shell can contain 2 electrons follwed by 8 electrons each till 3rd shell. However, starting from 4th shell, each electron shell can contains 18 electons.

Every atom has same number of Proton(+) and Electrons(+) for them to be electrically neutral. Both Proton and Neutrons have relative mass of 1. On the other hand, Electron has relatvie mass of 1/1840, which is negligible.

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