A small laboratory with dimensions 4.2 x 5 x 2.4 m is used to prepare a range of crude oil samples for analysis via GC—MS.

Question 4 — Chemico! Spfl’f A small laboratory with dimensions 4.2 x 5 x 2.4 m is used to prepare a range of crude oil samples for analysis via GC—MS. For one such preparation a small quantity of dichloromethane (DEM) is used to help separate polar and non—polar fractions from the oil sample using chromatography columns. A single 5 L bottle of high purity DCM is stored in the laboratory, with smaller working volumes directly decanted from the bottle as needed. Ifa worker in the lab decanted 450 mL of DCM into a beaker and left the laboratory urgently, without safely storing the decanted DCM, and the laboratory was closed over the weekend, what would be the concentration of DCM in the laboratory air the following week [you may assume complete evaporation, and no ventilation)? [4 marks) The density of DCM is 1330 kglma, the molecular weight is 84.93 gfmol. If the LEL of DCM is 13%, would this value be exceeded? (2 marks] If the IDLH value is 2300 ppm, is there an immediate danger to a worker entering the lab? (2 marks]