CHEMISTRY PRACTICAL ANSWERS [DA_CYBER _CYBER] NOTE THAT SUBSCRIBERS GETS THE ANSWERS FIRST BEFORE ITS BEEN POSTED HERE – ALWAYS SUBSCRIBE IF YOU NEED FAST AND EARLY RUNS
TABULATE
1ai)
Burette reading(cm³): |rough|1|2|3|Final reading:|23.80|33.00|45.40|28.50|Initial reading: |00.00|10.50|23.00|6.00|volume of acide used:|23.80|22.50|22.40|22.50|
1aii)
average volume of acid used = 1st titre 2nd titre 3rd titre/3average volume = 67.4/322.47cm³
1bi)
2Hcl Na2Co3 -> Back Co2 H2o 6.20g=0.5dm^3Conc. In gram/dm^3 =6.20/0.5=12.4g/dm^3Vol of b = pippete =25cm^3Conc. In mol/dm^3 =0.20mol/dm^3CaVa/CbVb=Na/Nb 0.20*22.4/Cb*25=2/14.48/25cb=2/150cb=4.48Fb=4.48/50=0.089mol/dm^3
1bii)conc(mol)=conc in g/dm^3 all over molar massNa2co3=23*2 12 3*16=106g/dm^30.20=conc in g/dm^3 all over 106Conc. In g/dm^3=0.20*106=1.2g/dm^3
1biii)
Mass pure/mass impure *100/1106/21.2*100=500g
2a
)i)is a mixture of soluble and insoluble saltii)filtrate is acidic
2b)
i)CL- present
ii)OBSERVATIONppt dissolvedINFERENCECL- confirmediii)INFERENCEgas is NH3 from NH4
2c)
i)the gas is acidic CO2 from CO3^2- orNCO3^-ii)black reside colourlessfiltrate, white pptthe precipitate dissolved white pptiii)the precipitate disolved
2d)i)ii)iii)ethanoliv)ethylhydrogen tetraoxosulphate(vi)
3)
i)NH3 has the highest rate of diffusionii)H2S smells like rotten eggiii)CO forms carboxyhaemoglobiniv)CL2 has a greenish-yellow colour
3bii)
SO4(g) 2FeCL3(aq) 2H20(l) —> 2FeCL2(aq) H2SO4(aq) 2HCL(aq)It reduces brown iron(ii)chloride sodium to green iron(ii)chloride solution and the sulphur(iv)oxide is oxidized to tetraoxosulphate(vi) acid.
3a)i)
NH3 has the highest rate of diffusionii)H2S smells like rotten eggiii)CO forms carboxyhaemoglobiniv)CL2 has a greenish-yellow colour
3bi)
FeCL2(aq) O2 ==> 2FeO(aq) CL2(g)It is observed that iron(II)oxide is formed and chlorine gas is liberated
3bii)
SO4(g) 2FeCL3(aq) 2H20(l) —> 2FeCL2(aq) H2SO4(aq) 2HCL(aq)It reduces brown iron(ii)chloride sodium to green iron(ii)chloride solution and the sulphur(iv)oxide is oxidized to tetraoxosulphate(vi) acid.
3c)oxides of hydrogen (H2O)
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Title :
100% NECO GCE 2016 CHEMISTRY PRACTICAL Answer Now Available Here
Description : CHEMISTRY PRACTICAL ANSWERS [DA_CYBER _CYBER] NOTE THAT SUBSCRIBERS GETS THE ANSWERS FIRST BEFORE ITS BEEN POSTED HERE – ALWAYS SUBSCRIBE I...
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