NYGH 2014-S3MYE-Chem P2

Class Register Number Name NANYANG GIRLS’ HIGH SCHOOL Mid Year Examination 2014 Secondary Three CHEMISTRY 1 hour 30 minutes Section B and C Theory Paper Tuesday 6 May 2014 1145-1315 Additional materials: Writing paper READ THESE INSTRUCTIONS FIRST Do not open this booklet until you are told to do so. Write your name, register number and class in the spaces at the top of this page and on any separate answer paper used. Section B (30 marks) Answer all questions. Write your answers in the spaces provided on the question paper. Section C (10 marks) Answer all questions. Write your answers on the separate writing paper provided. At the end of the examination, Hand in the writing paper separately. INFORMATION FOR CANDIDATES Examiner’s Use Section A Section B Section C Total The intended number of marks is given in the brackets [ ] at the end of each question or part question. Setters: LXT/ZJY This document consists of 9 printed pages. NANYANG GIRLS’ HIGH SCHOOL [Turn over

2014 Mid Year Examination Secondary Three 2 Nanyang Girls’ High School Setters: LXT/ZJY Chemistry Section B Answer all questions. Write your answers in the spaces provided. B1 A few drops of concentrated nitric acid were added to pieces of copper at the bottom of a tall bell jar. A reddish-brown nitrogen dioxide gas was formed and all the copper reacted in a very short time. The red-brown colour slowly moved up the gas jar but initially the colour remained darkest at the bottom. After thirty minutes, the reddish-brown colour was uniform throughout the gas jar. (a) Bromine is another reddish brown gas. Which gas, bromine or nitrogen dioxide, will fill up the whole jar in a lesser time? Give a reason for your answer. [2] (b) Explain how and why the results would differ if the gas jar was placed in hot water before carrying out the experiment. [2] Total [4] B2 Four elements P, Q, R and T, have proton numbers between 2 and 12. An atom of P has one electron less than a noble gas (Group 0 element). An atom of Q has three electrons less than a noble gas. An atom of R has one electron more than a noble gas. The atom of T has the same total number of electrons as P but the mass number of T is 1 more than that of P. (a) Write the chemical formula of the compound formed between (i) P and Q : __________________ [1] (ii) P and R : __________________ [1]

2014 Mid Year Examination Secondary Three 3 Nanyang Girls’ High School Setters: LXT/ZJY Chemistry [Turn over (b) Draw the Lewis dot diagram of the compound formed in (a)(i) [1] (c) What is the relationship between P and T? [1] Total [4] B3 A mixture of amino acid was separated by paper chromatography using two different solvents. After treating with a locating agent, the resu