Assignment (some Basic Concept Of Chemistry) - 3.pdf

  • Uploaded by: Jatin Singla
  • 0
  • 0
  • January 2021
  • PDF

This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA


Overview

Download & View Assignment (some Basic Concept Of Chemistry) - 3.pdf as PDF for free.

More details

  • Words: 904
  • Pages: 3
Loading documents preview...
Some Basic Concept of Chemistry (Assignment – 3) 1.

(a) A specimen of hematite contains 20%, Fe2O3. What weight of iron can be obtained from one ton of hematite?

(b) 6.0 g of sample of potassium chlorate (KClO3) gave 1.9g of oxygen on strong 2.

3.

4.

heating. What is the percentage purity of the sample? A one gram sample containing CaBr2, NaCl and some inert impurity is dissolved in enough water and treated with excess aqueous silver nitrate solution where a mixed precipitate of AgCl and AgBr weighing 1.94g was obtained. Precipitate was washed, dried and shaken with an aqueous solution of NaBr where all AgCl was converted into AgBr. The new precipitate which contains only AgBr now weighing 2.4 g. Determine mass percentage of CaBr2 and NaCl in the original sample. Sulphur combines with oxygen to form two oxides SO2 and SO3. If 10 g of S is mixed with 12g of O2, what mass of SO2 and SO3 will be formed so that neither S nor oxygen will be left at the end of reaction? 5.00 moles of hydrogen gas (H2), 3.00 moles of white phosphorus {P 4 (s)} and 12.00 moles of oxygen gas (O2) are taken in a sealed flask and allowed to react as follows:

H 2 (g)  P4 (s)  O 2 (g)  H 3 PO 4

5. 6. 7.

8.

Determine the moles of ortho-phosphoric acid that can be produced, considering that the reaction occurs in 100% yield. A 1 0 g sample of KClO3, gave on complete combustion, 2.24L of oxygen at NTP. What is the percentage purity of the sample of potassium chlorate? A mixture of CaCO3 and MgCO3 weighing 1.84 gm on heating left a residue weighing 0.96 gm. Calculate the % age of each in the mixture. A mixture of NaCl and Na2CO3 is given. On heating 12 gm of the mixture with dilute HCl, 2.241 gm of CO, is evolved at normal temperature. Calculate the amounts of two components in the mixture. Crude CaC2, is made in an electric furnace by the following reaction:

CaO  3C  CaC2  CO  The product contains 85% CaC2 and 15% unreacted CaO. (a) how much Cao is to be added to the furnace charge for each 1000 Kg of pure CaC2 produced? (b) How much CaO is to be added to the furnace charge for each 1000 Kg of crude product?

9.

Manganese trifluoride can be prepared by the following reaction: MnI 2 (s)  F2 (g)  MnF3  IF5 What is the minimum number of grams of F2 that must be used to react with 12.0 g of MnI2 if overall yield of MnF3 is no more than 75%.

10. Consider the following reactions:

XeF2  F2  XeF6 and XeF6  ( CH 2  CH 2 ) n   ( CF2  CF2 ) n  HF  XeF4 11.

Determine mass of F2(g) required for preparation of 1.0 kg fluorinated polymer. A pennsylvania bituminous coal is analysed as follows: Exactly 2. 5 gm is weighed into a fused silica crucible weighing 2.415 gm. The crucible next is covered with a vented lid and strongly heated until no volatile matter remains. The residue coke button weighs 1.528 gm. The crucible is then heated without the cover until all specks of carbon have disappeared, and the final ash weighs 0.245 gm. What are the percentage of moisture, volatile combustible matter (VCM), fixed carbon (FC) and ash?

12. (a) Calculate the % Na in a breakfast cereal which is advertised to contain 110 mg of sodium per 100 g of cereal. (b) l.12L CO2 gas at S.T. P. + 0.44 g CO2 - 6.02 × l0 molecules of CO2 = ______ moles of CO2. 13. A certain compound was known to have a formula which could be represented as [PdCxHyNz) (ClO4)2. Analysis showed that the compound contained 30.15% carbon and 5.06% hydrogen. When converted to the corresponding thiocyanate, [PdCxHvNz] (SCN)2, the analysis was 40.46% carbon and 5.94% hydrogen. Calculate the values-of x, y and z. [At. mass of Pd is 106] 14. In an electric arc tube A, 140 g N 2 is taken and in tube B, 20 g H2 is taken. When half the mass of substance in tube A is transferred to B, reaction took place in B. After the reaction is complete, half of the mass of substance in B is now transferred to A and again reaction will take place. Find out the final composition of gases in moles in A and B. [no reversibility] 15. A 'w' gm mixture of AgCl & AgBr undergoes a loss in wt. by 5% if it is exposed to excess chlorination. Calculate the percentage composition of the mixture.

Some Basic Concept of Chemistry (Assignment – 3)

Answer Key 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.

(a) 0.14 ton (b) 80.8 % of CaBr2 = 24, % of NaCl = 61 Mass of SO2 = 12 g, Mass of SO3 = 10g 3.33 81.6 45.65% of MgCO3, 54.35% CaCO3 6.594 NaCl (a) 1051.47 kg, (b) 893.75 kg 12.78 g 3.04 kg 3.4%, 35.48%, 51.32% FC, 9.8% ash 0.11% x = 14, y = 28, z = 4 A (2.084 mol N2; 3.33 mol NH3); B (1.25 mol H2; 2.5 mol NH3)] % AgBr = 21.12% AgCl = 78.88%

Related Documents


More Documents from "Lhoudielyn Fernandez Manlubatan"