Chemistry Past Questions and Answers

Equal volumes of CO<sub style='font-size: smaller;'>2</sub> cnd CO at s.t.p have the same

Gas molecules are said to be perfectly elastic because

What volume of hydrogen is produced at s.t.p. When 2.60 g of zinc reacts with excess HCI according to the following equation? Zn<sub style='font-size: smaller;'>(s)</sub> + 2HCI<sub style='font-size: smaller;'>(aq)</sub> → ZnCI <sub style='font-size: smaller;'>2(aq)</sub> + H<sub style='font-size: smaller;'>2(g)</sub> [Zn = 65; 1 mole of a gas occupies 22.4dm<sup style='font-size: smaller;'>3</sup> at s.t.p]

Helium is preferred to hydrogen in filling balloons because hydrogen

30cm<sup style='font-size: smaller;'>3</sup> pf hydrogen at s.t.p combine with 20cm<sup style='font-size: smaller;'>3</sup> of oxygen to form steam according to the following equation 2H<sub style='font-size: smaller;'>2(g)</sub> + O<sub style='font-size: smaller;'>2(g)</sub> → 2H<sub style='font-size: smaller;'>2</sub>O<sub style='font-size: smaller;'>(g)</sub>. Calculate the total volume of the gaseous mixture at the end of the reaction