Daily Question [091130—1201 Environmental Engineering Multiple Choice Questions]

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This post was last edited by zphero2008 on 2009-11-29 at 23:33. Currently, all members have the permission to use hidden replies; please cooperate actively. No scoring is given in principle if it is not hidden. For multiple accounts under the same IP, only the first response indicating participation is valid. Thank you all! To hide the method, click here: Hide Method. 1. For the determination of volatile phenols, methyl orange is used as an indicator, and the pH is adjusted using ( ) solution. A. Phosphoric acid B. Sulfuric acid C. Hydrochloric acid 2. When measuring suspended solids, the filter paper is dried in ( ). A、100–103°C B、103–105°C C、105–108°C 3. The potassium dichromate method for determining chemical oxygen demand is suitable for various types of samples with a COD value greater than ( ). A、10 mg/L B、20 mg/L C、30 mg/L 4. When determining ammonia nitrogen, the ammonium standard stock solution is prepared using ( ) dried at 100°C. A. Ammonium chloride B. Sulfuric acid an C. *ao acid an 5. The maximum allowable limit of hydrogen sulfide in the atmosphere is ( ) mg/m3. A、0.5 B、0.15 C、0.01 Everyone is welcome to participate actively; in principle, 3 points are awarded for each question. Those who answer all questions correctly will receive 15 wealth points, while those who answer some questions correctly will be scored based on the number of correct answers! To eliminate meaningless posts, abolish the minimum 5-point requirement! Note: Scores will be assigned and answers will be released uniformly after the topic is closed. Friends in the environmental protection industry and those interested in this field are encouraged to participate. Plagiarism is strictly prohibited, repeated posting is forbidden, and friend rating is prohibited; violators will have their points deducted!