Q1 Because of insufficient ignition, a supposed CaO precipitate from a 1 g
sample of limestone weighed 0.4125 g and contained 5.3% of its own
weight of CaCO3(ie there is CaCO3 left unignited whose
amount is 5.3% of 0.4132) . What is the reported and true percentage
of CaO (in the mixture)?
11another one
Q2
An iodide sample weighing 3.00 g is analyzed by dissolving into water and to this aqueous solution 50 ml 0.2 M AgNO3 was added. A 6.5 ml 0.1 KSCN solution was required to titrate the excess of silver ion present in the solution. Determine weight percentage of iodide in the sample.
can anybody at least provide the reactions involved......
11Q3 What is the equivalent weight of
(i) mohr's salt→ [FeSO4(NH4)SO4.6H2O]
(ii) pottasium ferrocyanide→ K4Fe(CN)6
39In Q1, the reaction is
CaCO3 -------> CaO + CO2
In Q2, the reaction is
MI + AgNO3 -----> MNO3 + AgI(ppt)
where M is any metal.
39SCN ke saath I think silver ion forms a complex, M[Ag(SCN)2] where M is a univalent metal. So here it should be K[Ag(SCN)2].
11for FAS I have seen in one question in RCM here Fe is getting oxidised from +2 to +3 (by the way it can only be oxidised to +3) & here the equivalent weight for FeSO4(NH4)SO4.6H2O is M/1
11Equivalent weight are not definite property for any compound. It depends on the reactions that a particular compound undergoes. Like potassium ferrocyanide has the eq wt of M/3 when it is reacted with Zn(+2) ion and when the same is reacted with H2O2 its eq wt is M/2. so if you just gave only the compound no one can predict its eq. wt correctly.
11now a very easy question ....what is the equivalent weight of elemental nitrogen N ?
11how???...is it always 14
calculate eq weight of N for this reaction:
NH3 +2O2 → HNO3 + H2O
