Chemistry Past Questions and Answers

Given that the molecular mass of iron is 56 and that of oxygen is 16, how many moles of iron(iii)oxide will be contained in 1kg of the compound?

3.0g of a mixture of potassium carbonate and potassium chloride were dissolved in a 25cm<sup style='font-size: smaller;'>3</sup> of this solution required required 40.00cm<sub style='font-size: smaller;'>3</sub> of 0.1M HCl for neutralization. What is the percentage by weight of K<sub style='font-size: smaller;'>2</sub>CO<sub style='font-size: smaller;'>3</sub> in the mixture. (K = 39, O = 16, C = 12)

Some properties of chemical substances are mentioned below... i. sour taste ii. slippery touch iii. yields alkaline gas with ammonium salt iv. has pH less than 7 v. turns phenolphthalein pink.<br/>Which of the above are NOT typical properties of alkalis?

A certain volume of gas at 298k is heated such that its volume and pressure are now four times the original values. What is the new temperature?

Hydrogen is not liberated when trioxonitrate(v)acid reacts with zinc because