Page 08 20. The following substance was analysed using an infrared spectrometer. C C C C C C H H H H H H H H H NH2 O The spectrum produced would not have a significant peak in the wave number range A 1700–1680 cm−1 B 2962–2853 cm−1 C 3100–3000 cm−1 D 3500–3300 cm−1. 21. Antisense drugs are a group of medicines that act by binding to DNA to block the synthesis of some proteins. Which line in the table is correct for antisense drugs? Classification Receptor A antagonist DNA B antagonist protein C agonist DNA D agonist protein 22. Which of the following would be most suitable as a reagent in the gravimetric analysis of silver ions? A Sodium nitrate B Potassium sulfate C Barium carbonate D Ammonium chloride