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Showing posts with label STOICHIOMETRY:. Show all posts
Showing posts with label STOICHIOMETRY:. Show all posts

Sunday, May 9, 2021

Write the POAC equations for all the atoms in the following reaction.

Illustrative solution:

Applying POAC on (P) atoms:

                                                    P à H3PO4

Numbers of moles of (P) atoms in P4 = Numbers of moles of (P) atoms in H3PO4

                                               4x nP4= 1x nH3PO4

Applying POAC on (H) atoms:

                                       1x nHNO3 = 3 x nH3PO4 + 2 x nH2O

Applying POAC on (N) atoms:

                                       1 x nHNO3 = 1 x nNO2

Applying POAC on (O) atoms:

                                       3 x nHNO3 = 4 x nH3PO4 +2 x nNO2 + 1nH2O

Related Questions:

Principle of atom conservation (PAOC):

Illustrative example (2) 27.6 gm K2CO3 (138) was treated by a series of reagents so as to convert all its carbon into K2Zn3[Fe(CN)6]2(MM=698) Calculate mass of K2Zn3[Fe(CN)6]2.

In a determination of P an aqueous solution of NaH2PO4 is treated with a mixture of Ammonium and magnesium ions to precipitate magnesium Ammonium phosphate (Mg(NH4)PO4.6H2O. This is heated and decomposed to magnesium pyrophosphate. Which is weighed. A solution of NaH2PO4 yield 3.33 gm of Mg2P2O7. What is weighed of NaH2PO4 was present originally.


Related Questions:

Principle of atom conservation (PAOC):

For BaCl2.XH2O , 2.1 gm of Compound gives 2 gm of anhydrous BaSO4 (M.mass =233)upon treatment with H2SO4 then calculate value of X.

 

Related Questions:

Principle of atom conservation (PAOC):

All the carbon atom present in KH3(C2O4)2.2H2O weighting 254 gm is converted to CO2. How many gram of CO2 were obtained.

 Illustrative solution:


Related Questions:

Principle of atom conservation (PAOC):

0.32 gm mole of LiAlH4 in ether solution was placed in a flask and 74 gm (1 mole ) of t- butyl alcohol was added . The product is LiAlHC12H27O3. Calculate mass of product if all lithium atoms are converted.

Illustrative solution:

By applying POAC on (C) atoms:

Related Questions:

Principle of atom conservation (PAOC):

27.6 gm K2CO3 (138) was treated by a series of reagents so as to convert all its carbon into K2Zn3[Fe(CN)6]2(MM=698) Calculate mass of K2Zn3[Fe(CN)6]2.

 Here all the carbon of K2CO3 converted into a complex hence POAC can apply

Related Questions:

Sunday, December 6, 2020

A plant virus is found to consist to uniform cylindrical particles of 150Å in diameter and 5000Å long. The specific volume of the virus is 0.75 cm3/g. What is the molecular mass of virus ?

 

Related Questions:

Calculate the amount of 80 % pure NaOH sample required to react with 21.3 gm Chlorine in hot condition.



A sample of impure Iron pyrite (FeS2) when 13.9 gm heated then it produces iron (iii) oxide (Fe2O3) and Sulphur dioxide (SO2). If 8.02 gm Iron (iii) oxide is obtained, what was the % purity of given sample (original-FeS2)?








Thursday, October 1, 2020

25 ml of household bleach solution was mixed with 30 ml of 0.50 M KI and 10 ml of 4.0N acetic acid. In this titration of the liberated iodine 48 ml of 0.25 N Na2S2O3 was used to reach the end point. The Molarity of household bleach solution is?

Calculate the % of available chlorine in the sample in a sample of 3.35 gm of bleaching powder which was dissolved to 100 ml water. 25 ml of this solution on treatment react with KI and dilute acid. Required 20 ml 0.125 N Hypo solution (Sodiumthiosulphate- Na2S2O3).

Related Questions:

What are the Antichlor ?

An antichlor  is a substance used to decompose residual hypochlorite or chlorine after use of chlorine based bleaching , in order to prevent ongoing reactions .example s of antichlor – Sodiumbisulphite (NaHSO3), Pottassiumbisulphite (KHSO3) ,  Sodiummetasulphite (Na2S2O3), Sodiumthiosulphate  (Na2S2O3) and hydrogen peroxide (H2O2).

If trace of chlorine are not remove from pulp used for paper manufacturing,then on the long standing it weaken the paper and makes it yellowish. 

Related topics: 

Mole concept and Stiochiometry

MOLE-MOLE ANALYSIS

 CONCEPT OF LIMITING REAGENTS 

GRAVIMETRY-WEIGHT WEIGHT ANALYSIS

 OLEUM AND ITS PERCENTAGE(%) LABBELING

VOLUME STRENGTH OF H2O2(aq) 

 PRINCIPLE OF ATOM CONSERVATION (PAOC) 

 GRAVIMETRY-WEIGHT WEIGHT ANALYSIS 

EUDIOMETRY-VOLUME VOLUME ANALYSIS OF GAS 

DEGREE OF HARDNESS OF HARD WATER 

PERCENTAGE YIELD OF CHEMICAL REACTION: 

PERCENTAGE PURITY OF GIVEN SAMPLE:

PERCENTAGE (%) AVAILABLE CHLORINE IN BLEACHING POWDER:

 

 

If 4 gm of bleaching powder dissolved to give 100 ml solution 25 ml of it react with excess of CH3COOH and KI .The Iodine liberation required 10 ml of 0.125 N Hypo solutions. Calculate % of available chlorine in the sample.

Available chlorine in sample of bleaching powder can be calculated as per the following reactions.



Wednesday, April 29, 2020

Air contains 20℅ O2 by Volume.How many cc of air will required for oxidation of 100 cc of acetylene?

0.0833 moles of a carbohydrate having empirical formula of CH2O contains one gram hydrogen, find molecular formula

Given EF= CH2O then mass=30
And carbohydrate(CH2O) contains 1gram hydrogen:
From EF it is obvious that 2 grams hydrogen present in 30 grams then 1grams hydrogen present in 15 grams corbohydrate.

Number of moles = Given mass/M.Mass
                              0.0833  =15/M.mass
Then M.mass=180

We Must needed 
Molecular Formula(MF) = n× Empirical Formula (EF)
MF=6(CH2O) = C6H12O6
Where n = Molecular mass/Empirical mass
             n= 180/30=6

Friday, April 24, 2020

A six co-ordinate complex of formula CrCl3.6H2O has green colour. One litre of O.1M solution of the complex when treated with excess of AgNO3 gave 28.7 g of white precipitate. The formula of the complex is .... (1) [Cr(H2O)6]CI3 (2) [Cr(H2O)5CI]CI2.H2O (3) [Cr(H2O)4CI2]Cl.2H2O (4) [Cr(H2O)3Cl3].3H2O

SOLUTION: 

Given 28.7 g of white ppt obtained is 28.7/147.5= 0.2 mole Agcl precipitate Since 0.1M complexgives 0.2 mole AgCl means 2Cl− are ionisable or two Cl- ion must be present out of coordination sphere so, complex is [Cr(H2​O)5​Cl]Cl2​.H2​O