Four students added a small amount of ethanoic acid to sodium hydrogencarbonate. The gas evolved was tested for its behaviour with burning splinter and lime water. They reported their observations as given below.<br><img src="/assets/questions/media/Pg%20315_31.png" class="progressive" data-href="https://img-nm.mnimgs.com/img/study_content/content_ck_images/images/Pg%20315_31.png"><br><table class="table table-bordered"><tbody><tr><td>Student</td><td>Gas evolved</td><td>Action on burning splinter</td><td>Action on lime water</td></tr><tr><td>A</td><td>CO<sub>2</sub></td><td>The flame of splinter extinguishes and gas does not burn</td><td>Turned milky</td></tr><tr><td>B</td><td>SO<sub>2</sub></td><td>The splinter burns brightly and the gas burns with a pop</td><td>Turned green</td></tr><tr><td>C</td><td>NO<sub>2</sub></td><td>The gas does not burn but the splinter burns with a hissing sound</td><td>Turned black</td></tr><tr><td>D</td><td>O<sub>2</sub></td><td>The gas burns with a yellow flame and the splinter extinguishes</td><td>Turned purple</td></tr></tbody></table><br>The correct observations have been reported by student:<br><b>(1)</b> A <br><b>(2)</b> B<br><b>(3)</b> C <br><b>(4)</b> D"