WAEC Chemistry Past Questions & Answers - Page 155

Which of the following gases has the lowerst rate of diffusion under the same conditions of temperature and pressure? [H = 1, O = 16, Ne = 20, CI = 35]

Consider the reaction represented by the following equation: Zn_(s) + 2HCI_(aq) → ZnCI_2(aq) + H_2(g) what volume of hydrogen gas is produced at s.t.p. when 3.25 g of zinc reacts with excess dilute HCI? [Zn = 65, Molar gas volume at s.t.p. = 22.4 dm^-3]

If 5.00cm³ of 0.20 mol dm^-3Na₂CO₃ was diluted with distilled water to obtain 250 cm³ solution, what is the concentration of the resulting solution?

Which of the following compounds with the corresponding masses contain the highest percentage of nitrogen? [N = 14]

What is the mass of 6.02 x 10²⁴ atoms of magnesium? [Mg = 24, Avogadro constant = 6.02 x 10²³ atoms mol^-1]