Chemistry Past Questions and Answers

An acid and its conjugate base

The same current is passed for the same time through solutions of AgNO<sub style='font-size: smaller;'>3</sub> and CuSO<sub style='font-size: smaller;'>4</sub> connected in series. How much silver will be deposited if 1.0 g of copper is produced?<br/>[Cu = 63.5, S = 32, O = 16, Ag = 108, N = 14]

What is discharged at the cathode during the electrolysis of copper (ll) tetraoxosulphate (VI) solution?

An element, Z froms an anion whose formula is [Z(CN)<sub style='font-size: smaller;'>6</sub>]<sup style='font-size: smaller;'>y</sup>. If Z has an oxidation number of +2, what is the value of y?

The combustion of ethene, C <sub style='font-size: smaller;'>2</sub>H <sub style='font-size: smaller;'>4</sub>, is given by the equation C <sub style='font-size: smaller;'>2</sub>H <sub style='font-size: smaller;'>4</sub> + 30 <sub style='font-size: smaller;'>2</sub> → 2CO<sub style='font-size: smaller;'>2</sub> + 2H<sub style='font-size: smaller;'>2</sub> O; ∆H = - 1428 KJ. If the molar heats of formation of water and carbon (IV) oxide are - 286 kJ and - 396 kJ respectively, calculate the molar heat of formation of ethene in KJ