OCR A Jun 2014 Paper 1 Q1

Answers available below

Answer all the questions. 1 Antimony, Sb, has atomic number 51. (a) Complete the table below to show where antimony is found in the Periodic Table. Period Block PMT [1] (b) Antimony exists as a mixture of isotopes. (i) What is meant by the term isotopes?[1] (ii) Different isotopes of antimony have the same chemical properties. Explain why.[1] (iii) Complete the table below to show the atomic structure of 121Sb. Protons Neutrons Electrons [1] (c) The relative atomic mass of antimony is 121.8. (i) Define the term relative atomic mass.[3]OCR 2014<br />
 (ii) A sample of antimony, Ar = 121.8, was analysed and was found to consist of 60% 121Sb and one other isotope. Determine the mass number of the other isotope in the sample of antimony. PMT mass number of the other antimony isotope =[1] (d) Antimony chloride, SbCl3, exists as simple covalent molecules. A dot-and-cross diagram of SbCl3 is shown below. Cl Sb Cl Cl (i) Predict the shape of a molecule of SbCl3. Explain your answer. name of shape:explanation:[3] (ii) SbCl3 molecules are polar. Explain why.[2] [Total: 13]OCR 2014 Turn over<br />

Show answer