Chemistry Past Questions and Answers

9.8g of solid potassium chlorate (KCIO<sub style='font-size: smaller;'>3</sub>) were added to 40 cm<sup style='font-size: smaller;'>3</sup> of water and heated to dissolve all the solid. As he solution cooled, crystals of potassium chlorate started forming at 60°C. The solubility of potassium chlorate at 66°C is therefore?

100 cm<sup style='font-size: smaller;'>3</sup> of oxygen is made to react with 50 cm <sup style='font-size: smaller;'>3</sup> of hydrogen, and the whole reaction mixture was then passed through anhydrous calcium chloride. What is the volume of gas left?

A mixture contains 20cm<sup style='font-size: smaller;'>3</sup> of hydrogen, 35cm<sup style='font-size: smaller;'>3</sup> of oxygen, 15cm<sup style='font-size: smaller;'>3</sup> of carbon monoxide and 10cm<sup style='font-size: smaller;'>3</sup> of nitrogen at S.T.P. Which of the following gives the mole fraction of hydrogen in this mixture?

0.07g of a hydride of carbon occupies 56.0cm<sup style='font-size: smaller;'>3</sup> at S.T.P. when vaporized and contains 14.29% by mass of hydrocarbon is(C = 12, H = 1)

The pressure on 100 cm<sup style='font-size: smaller;'>3</sup> of oxygen gas at 35°C is 750mm of Hg.What would be the volume of the gas if the pressure is increased to 1000mm of Hg without changing the temperature?