Three elements from Group 1 and three elements from Group 17 are given in the table with their relative atomic masses.Group 1 Group 17lithium (7) fluorine (19)sodium (23) chlorine (35.5)potassium…
The compounds BrCl and BrI melt at – 66 °C and 42 °C, respectively. What is the best explanation for this difference in melting points? Answer:
Complete combustion of 35 cm3 of a straight-chain alkane vapour gave 105 cm3 of carbon dioxide gas. Both gas volumes were measured at the same temperature and pressure. Which of…
A compound of oxygen and fluorine has a relative molecular mass which is twice that of its empirical formula mass. 105 g of the compound contains 57 g of fluorine.…
Hydrated copper(II) sulfate has the formula CuSO4·5H2O. 100 cm3 of a solution contained 10 g of hydrated copper(II) sulfate. What is the concentration, in mol / dm3, of this solution?…
Calcium carbonate reacts with hydrochloric acid. The reaction gives off carbon dioxide gas. Line X on the graph shows the volume of carbon dioxide formed against time when 100 cm3…
Which of the following have the same electron arrangement? Answer: 2) C In order to answer the question, we only need to find out how many electrons each of the…
Graphene is a new material composed of carbon atoms arranged in tightly bound hexagons just one atom thick.The diagram shows a simplified structure of graphene.Considering its structure, which of the…
By using standard techniques to balance chemical equations and ensuring that the net charge is equal on both sides, find the correct value for ' e ' in the balanced…
Tritium, symbol T, is hydrogen with a mass number of 3. It is radioactive and undergoes βdecay.Which of the following could be the only product(s) after a quantity of HTO…