Kickstart scheme

English143

Qwerty

(edited 2 years ago)

Reply 1

Sodium229

Original post by English143

Thanks

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1) For the first question, I think you need to write about the temporary dipoles. This has to do with the electrons constantly moving within the chlorine atoms, so when chlorine molecules are moving around each other, temporary dipoles occur and this induce dipoles to other surrounding Cl2 molecules, in which partial charges delta + and delta - are formed in chlorine molecules and attract each other, therefore weak London Forces (or Van Der Waal's forces if your exam board does not allow the term London Forces) are formed between the chlorine molecules.
2) The second question is basically the equation for the chlorination of water, the equation is:
Cl2(g) + H2O(l) -> HClO(aq) + HCl(aq)
The reason for that is, chlorine kills bacteria so the water is safe to drink.
3) The equation for third question is:
Cl2(aq) + 2NaOH(aq) -> NaClO(aq) + NaCl(aq) + H2O(l)
4) For my exam board, the first positive ion that came to my mind in this case is Ba2+ ions.
The ionic equation is just: Ba2+(aq) + SO42-(aq) -> BaSO4(s)
Whenever there is effervescence, carbonate is usually present and the gas produced in test 1 is therefore carbon dioxide.
And since the gas produced in test 2 turned the damp red litmus paper blue, the gas therefore is ammonia and the solution B consists of ammonium ions, NH4+, hence the ionic equation for the formation of ammonia, NH3, would be:
NH4+(aq) + OH-(aq) -> H2O(l) + NH3(g)

(edited 2 years ago)

Reply 2

Sodium229

I know you do not have time to understand everything before tomorrow therefore I sent my solutions without really explaining it, take a look at the following pages, it will help you with your understanding of these types of questions:
Intermolecular forces: https://www.chemguide.co.uk/atoms/bonding/vdw.html
Chlorination of water: http://www.chemguideforcie.co.uk/section94/learningij.html
Reaction of chlorine with cold sodium hydroxide solution: http://www.chemguideforcie.co.uk/section94/learningh.html
Tests for negative ions and halide ions: https://www.chemguide.uk/14to16/analysis/anions.html
Tests for positive ions: https://www.chemguide.uk/14to16/analysis/cations.html
Also check your specification to see which content you need to know, also check out https://chemrevise.org, it is a great website for chemistry revision :smile: