Some questions on Chemistry

• anpanman

  7 Jul 09, 18:04

  1 Does both K2O and CaO reacts with ammonium salt to liberate NH3 gas?

  2 Next, is Ni(NO3)2.6H2O coloured?

  And if the question asks When water is added to the sample, it dissolves readily to form a colourless solution.

  Is BaCl2.2H2O under this category? Well, isn't BaCl2.2H2O already a solution?

  Thanks.

   

• SBS n SMRT

  7 Jul 09, 18:54

  Originally posted by anpanman:

  1 Does both K2O and CaO reacts with ammonium salt to liberate NH3 gas?

  2 Next, is Ni(NO3)2.6H2O coloured?

  And if the question asks When water is added to the sample, it dissolves readily to form a colourless solution.

  Is BaCl2.2H2O under this category? Well, isn't BaCl2.2H2O already a solution?

  Thanks.

   

  2. Not coloured. Btw, where u get this qns..seems familar

• ThunderFbolt

  7 Jul 09, 20:07

  3. Could be BaCl2.2H2O.

  The (2H2O) at the back means that the salt is hydrated. Just like copper sulphate got white color and blue as one is anhydrous (got no water) and pentahydrate (attached with 5 molecules of water). 

   

  Can read more about it here: http://en.wikipedia.org/wiki/Water_of_crystallization

• anpanman

  7 Jul 09, 20:23

  Originally posted by SBS n SMRT:

  2. Not coloured. Btw, where u get this qns..seems familar

  
  Thanks.

  It's from victoria school prelims 08

• UltimaOnline

  7 Jul 09, 21:35

  Originally posted by anpanman:

  1 Does both K2O and CaO reacts with ammonium salt to liberate NH3 gas?

  2 Next, is Ni(NO3)2.6H2O coloured?

  And if the question asks When water is added to the sample, it dissolves readily to form a colourless solution.

  Is BaCl2.2H2O under this category? Well, isn't BaCl2.2H2O already a solution?

  Thanks.

   

   

  Q1. Proton transfer from ammonium cation, Bronsted-Lowry acid, to the oxide ion or hydroxide ion (if aqueous environment), the Bronsted-Lowry base. When NH4+ is deprotonated, what do you get?

  Q2. Ni2+ is [Ar] 4s0 3d8, has partially filled d-orbitals and hence have d-d electron transitions. For the colour, visit http://en.wikipedia.org/wiki/Nickel(II)_nitrate

• anpanman

  9 Jul 09, 19:58

  Hi everyone!

  Hmm, BaCl2 reacts with AgNO3 to form Ba(NO3)2 and AgCl but what happens when hydrated BaCl2 (BaCl2.2H2O) reacts with AgNO3?

  Thanks!

• lavastar

  9 Jul 09, 21:04

  Originally posted by anpanman:

  Hi everyone!

  Hmm, BaCl2 reacts with AgNO3 to form Ba(NO3)2 and AgCl but what happens when hydrated BaCl2 (BaCl2.2H2O) reacts with AgNO3?

  Thanks!

  
  since it is mentioned that BaCl2 is hydrated, u can assume it exists as Ba2+ and CL- ions in water. AgNO3 is completely soluble in water, so there is Ag+ and NO3- ions inside it too. So when Ag+ and Cl- ions come together, they will form AgCl, which is insoluble. hence a white precipitate will be seen.

• Babelfish

  9 Jul 09, 21:09

  lol.. now secondary already started  teaching about Bronsted lowry and spdf notations le?

• ThunderFbolt

  9 Jul 09, 21:41

  Originally posted by lavastar:

  
  since it is mentioned that BaCl2 is hydrated, u can assume it exists as Ba2+ and CL- ions in water. AgNO3 is completely soluble in water, so there is Ag+ and NO3- ions inside it too. So when Ag+ and Cl- ions come together, they will form AgCl, which is insoluble. hence a white precipitate will be seen.

  hydrated and aqueous form not same leh. hydrated means that water molecules are bonded to the compound but the substance can still be dry. nothing will happen in both cases. 

• SBS n SMRT

  12 Jul 09, 22:07

  Originally posted by anpanman:

  
  Thanks.

  It's from victoria school prelims 08

  no wonder....u fm VS?