Salt analysis

A 0.81g sample of pyrolusite ore(impure MnO₂) is treated with

1.651 g of oxalic acid (H₂C₂O₄.H₂O)

in an acidic medium.Following this reaction the excess oxalic acid is

treated with 0.1M KMNO₄ , 30.6 ml being required.What is

the % of MNO₂ IN the ore

H₂C₂O₄ + MnO₂ + 2H⁺ → Mn²⁺ + 2H₂O + 2CO₂

5 H₂C₂O₄ + 2 MnO₄^- + 6 H⁺ → 2 Mn²⁺ + 8 H₂O + 10 CO₂

for post no.26----------------sodium and potassium

ans to the [Zn⁺²] question should be (c) according to le-chatlier principle

Nitrite + acetic acid + thiourea → N₂+SCN^-+2H₂O

Formation of the product in the above reaction can be identified by:

(a) FeCl₃/dil.HCl when blood red colour appears

(b) FeCl₃/dil.HCl when blue colour appears

(c)K₂Cr₂O₇/dil.HCl when green colour appears

(d) KMnO₄/Hcl when colourless sol is formed.

The reaction

4MO₂(S) + 2CO₂(g) → 2M₂CO₃(s) + 3O₂(g)

is to be used to regenarate oxygen in space-craft.
Can anyone tll me the choice of M among alkali metals...

In strongly alkaline sol containing excess of barium ions,a sol containing

0.01587g of I^- was treated with o.1 molar MnO₄^-

until a pink colour persisted in the sol:

10.0ml of the MnO₄^- sol was required.under these

conditions MnO₄^- is converted into the sparingly soluble

BaMnO₄.What is the product of the oxidation of iodide?

Last one :

A - NH₄NO₃
B - H₂O
C - N₂O
D - P₄O₁₀

HINT : only oxide liquid at room temp. possible is perhaps H₂O. that stong dehydrating agent struck for P₄O₁₀. AND finally dat 250⁰C data struck for NH₄NO₂.

FOR PREVIOUS ONE its perhaps HCl (aq.).

To increase significantly the conc of free Zn²⁺ion in a sol of the

complx ion [Zn(NH₃)₄]²⁺,

Zn²⁺(aq)+ 4 NH₃ (aq) → [Zn(NH₃)₄]²⁺(aq)

add to the sol some:

(A) H₂O

(b) HCl(aq)

(c) NH₃(aq)

(D) NH₄Cl(aq)

not sure, but perhaps c). seen somewhere.

Fulminating gold is:

(a) AuCl₃

(b) Au₂S

(c) Au(NH₂) = NH

(d) H[Au(Cl)₄)]

Philosopher's wool on treatment with cobalt nitrate produces

(a) CoBaO₂

(b) CoZnO₂

(c) CoSrO₂

(d) CoMgO₂

accord to me `a` is the right answer.

as its 5 water molecules associated with it. and it melts at 30 degree celcius (which is room temp generally)

The action of conc H₂SO₄ on urea results in
the production of a white crystalline solid X of formula H₃ NO₃S,a monobasic acid. on treatment with sod nitrite and dil.HCl at 0 degree.it liberates one mol of N₂ per mol of X, and on addition of aq. barium chloride, the resulting sol yields one mol of BaSO₄ per mol of X taken. Deduce the structure of X.

wikipedia will made us mad.

@ msp and everyone
here is the content from wiki to support my answer
""Deliquescent materials are substances (mostly salts) that have a strong affinity for moisture and will absorb relatively large amounts of water from the atmosphere if exposed to it, forming a liquid solution. Deliquescent salts include calcium chloride, magnesium chloride, zinc chloride, potassium carbonate, potassium phosphate, carnallite, ferric ammonium citrate, potassium hydroxide and sodium hydroxide. ""

if u wanna cross-check urself ,here is the link
http://en.wikipedia.org/wiki/Hygroscopy

http://en.wikipedia.org/wiki/Category:Deliquescent_substances

eure for the second b cant be as the gp1 metals wont get hydrated.

perhaps its NH₄⁺ because:

a) it normally forms strong ionic bonds
b) its precipitates r thermally vry stable, as they r easily formed under thermodynamically controlled conditions

The ion most difficult to remove as a ppt is

(A) Ag⁺

(b) NH_4⁺

(c) Fe³⁺

(d) Cu²⁺