Tag: chemistry

Confirmed Questions & answers for Neco chemistry practical

NECO-CHEMISTRY-PRACTICALS-ANSWER 1ai) Tabulate Titrations|Rough|first(1)|second(2)|third(3) Final burette reading-|20.50|14.90|15.00|15.10| initial burette reading- |0.00|0.00|0.00|0.00| volume of Acide used- |20.5|14.90|15.00|15.10| 1ai) average volume of Acid used 1st+2nd+3rd/3 14.90+15.00+15.10/3=45/3=15cm^3 1aii) 2HCL(aq)+Na2CO3(aq)—->2NaCl(aq)+H2O(aq)+CO2(aq) 1bi) CA VA/CB VB =NA/NB 0.1moldm^-3*15cm^3/CB*25cm^3 *2/1 CB * 25cm^3*2=0.1moldm^-3*15cm^3*1 CB * 50=1.5 CB=1.5/50=0.03moldm^-3 1bii) 25cm^3—->0.03mole 1000cm^3—->x x=1000*0.03/25=30/25 x=1.2moldm^-3 1biii) concentration in mold^-3 =Con glm^3 /molar mass 0.03moldm^-3=x/106 x=0.03*106 […]

NABTEB CHEMISTRY EXPO RUNS SOLUTIONS 2018

NABTEB CHEMISTRY Nabteb Chemistry Obj 1AADDDCACCC 11DAACAABCDC 21ABABDCDCAC 31BDCCADBBBA 41DCDBDDDBAB (1ai) An element is a substance that cannot be split into simpler substances by any known chemical process. (1aii) Limestone ==> CaCo3 TABULATE |Elements| Group| UNDER ELEMENT: (i) Calcium (ii) Carbon (iii) Oxygen UNDER GROUP: (i) II (ii) IV (iii) VI (1bi) Hund’s rule of […]