Chemistry Past Questions and Answers

A given quantity of a gas occupies a volume of 228 cm<sup style='font-size: smaller;'>3</sup> at a pressure of 750mm Hg. What will be its volume at atmospheric pressure?

A sample of a gas exerts a pressure of 8.2 atm when confined in a 2.93 dm<sup style='font-size: smaller;'>3</sup> container at 20°C. The number of moles of gas in the sample is?<br/>(R = 0.082 litre atm / deg mole)

Atoms of element X (with 2 electrons in the outer shell). combine with atoms of Y (with 7 electrons in the outer shell). Which of the following statements is FALSE? The compound formed?

The electronic configuration of an elements is 1s<sup style='font-size: smaller;'>2</sup>2s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup>3s<sup style='font-size: smaller;'>2</sup>3p<sup style='font-size: smaller;'>3</sup>. How many unpaired electrons are there in the element?

The ions X<sub style='font-size: smaller;'>-</sub> and Y<sub style='font-size: smaller;'>+</sub> are isoelectronic, each containing a total of 10 electrons.<br/>How many protons are in the nuclei of the neutral atoms of X and Y respectively?