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

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?

A colourless inorganic salt (A) decomposes completely at abt 250

celsisus to give onli 2 prodcts (B) and (c) leaving no residue.The

oxide (c) is a liquid at room temp and neutral to moist litmus

paper whil the gas (B) is neutral oxide.White phosphorus burns

in excess of (B) to poduce a strong white dehydrating

agent(D). Write eqs for the reactions involved in the process..

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)]

dude,philosopher's wool is ZnO (zinc oxide)
thus answer is b) CoZnO₂.

the other one i'll post tomorrow.

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 Answer is obviously (a) because NaOH is not Deliquesent and SiO₂ is sand
You can test it to BE deliquesent by just seeing it in a plant

ya,this H₃NO₃S is Sulfamic acid.

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.

eureka if ncert and jd lee were rite i can say dat sodium ion has lesser hydration enthalpy inorder to overcome its lattice energy.

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

option A ??

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