Chemstry question and amser now available 2a.i. Inference: dissolve to give colorless solution Observation: soluble salt ii. inference:effervescent of gas which is acidic to litmus observation: C03^2- and HC03 Suspect b.i. X is ammonia (NH3) ii. Y is ammonium chloride (NH4CL) iii.Z is nitrogen (ii)oxide (N0) C. i.the solution will turn to black due to formation of black lead (ii) sulphide ii.The solution change from orange to green by reducing to chromium (iii)tetraoxosulphate (vi) 3a. i. delivery tube ii. Combustion tube iii. water troue iv. gas jar 3a.ii W is hydrogen iii. it burns with pop sound production iv. i.it will be oxidize to water ii.it will reduce cuo to metallic copper b. i.the gas is collected over the water II. i.the purple color of KMNO4 become colorless II.ii.yellow precipitate is produced 3c. red precipitate would be observed to indicate that it is reducing sugar Nabteb Gce Comfrim Chemistry questions. +++++++++++++++++++++++++ (1ai)Copy and complete the table recorded by a student during a tritration exercise. Pls draw a table BURETTE READINGS(cm3) |Rough|1|2|3| FINAL |31.00 | ____ | 33:15 | 31.50 | INITIAL | 2.50 | 1.45 | ___ | 3.40 | VOLUME OF ACIDE USED | ___ | 28.05 | 28.75 | ___ | (1ai)Calculate the average of titre values obtained in (a) (i) (1b)Given that the acid used for the titration is hydrogen chloride acide solution containing 4.10gdm-3 it neutralized 25.0cm3 portion of an alkali (Y0H) solution which contained 7.00gdm-3 calculate the (i)concentration of hydrogen chloride acide solution is moldm-3 (ii)concentration of YOH solution in moldm-3 (iii)Molar mass of YOH and hence the relative atomic mass of Y correct to the nearest whole number. (iv)Name the element Y The equation for the reaction is HCl+YOH--->YCl+H2O(1) [HCl=36.5;H=1.00; O=16.0] (1c)List four preacautions necessary to ensure accurate results during titration (2a)The following shows the recorded tests performed on samples D and E which were sodium trioxocarbonate(Iv) crystals and iron (III) tretraoxosulphate(VI)crystals respectively. Copy out the table and state the observations made in each test. |TEST| (i)D + distilled water shake well. (ii)Portion of D solution + dilute H2SO4 + warm (iii) E + distilled water shake well and test with litmus paper (iv)Portion of solution D mixed with solution E | OBSERVATION | (i)_________________ (ii)_________________ (iii)_________________ (iv)_________________ (v)Name the type of reaction between solutions D and E (2bi) A colourless gas X has a choking smell,forms white dense fumes,Y with hydrogen chloride gas the same gas X reacts with oxgen (air) in the presence of heated suitable catalyst to form another colourless gas which rapidly reacts wit more air to form brown fumes Z Using the above imformation identify X,Y,Z (2c) State what is observed when (i)H2S gas is bubbled into a solution of Pb(NO3)2 (ii)SOgas is bubbled into a solution of acidified K2 Cr2 O7 solution. (3a)The set_up of apparatus illustrated below is for the preparation of gas, W from iron filling and steam. ********Drawing*********** (i)Name the pieces of apparatus labelled I,II,III and IV (ii) Identify W (iii)Give the laboratory test for the gas W (iv) State two observation if W was passed over a heated sample of copper(II)oxidepowder. (3b)Ethyne is prepared in the laboratory by the action of cold water on calcium carbide (3bi)State how the dry gas can be collected. (3bii)What would be observed if the gas is passed through (i)acidified KMnO4 solution br /> (ii)ammoniacal silver trioxonitrate (V)solution (3c)State what would be observed when a few drops of Fehlings solution is added to 5cm of gluecose solution in a test tube and the content boiled. ========================= 4more answer vist argungufanz.nazuka.net
Posted on: Mon, 10 Nov 2014 07:44:18 +0000
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