【Weekly Topic】(Forty-two) 2015.9.9 Multiple-choice Question

Thread Content

This post was last edited by zjp on 2015-9-9 at 17:47. To improve the weekly topics, this week’s topic has been changed to 5 multiple-choice questions, in order to determine the number of posts posted and thus decide on the content for next week’s topics. 5 multiple-choice questions; 2 points are awarded for each correct answer, for a total score of 10 points. All sea friends are encouraged to participate actively in the quizzes. Just write down the serial number of the correct answer for each question. 1. The molar concentration refers to ( ). A The amount of substance per unit mass of solution B The amount of substance per unit volume of solution C The mass of substance per unit volume of solution D The amount of solute per unit volume of solution 2. The unit for amount of substance is ( ). A g B kg C mol D mol/L 3. When an electrical appliance is on fire and the power supply has not been turned off, which type of fire extinguisher or extinguishing agent can be used to put out the fire? ( ). A. Foam fire extinguisher B. Water C. Carbon dioxide fire extinguisher D. 1211 fire extinguisher 4. In the event of a small fire in a laboratory, which of the following actions is the correct one to take? ( ) A. Zhang panicked and fled the scene. B. Seize the moment the fire started, quickly extinguish it and turn off the heat source, removing flammable materials and valuable instruments. C. Take no action to put out the fire and just go to call for help. D. Use water to extinguish the fire. 5. When clothing catches fire, which of the following actions is correct? ( )A. The person who was burned ran away from the scene. B. The person who was burned stayed where they were, lying on the floor and trying to extinguish the flames. C. Immediately took off their clothes. D. Did nothing to put out the fire, only going to get someone else to do it. 1