Chemistry 1st Ch 01 Safe Use of Laboratory

Chemistry - First Paper Chapter 1: Safe Use of Laboratory Selected Questions and Answers (HSC English Version) 0.1 Chapter 1: Safe Use of Laboratory Group A: Knowledge Based Questions [At a Glance] (1) Laboratory Rules: 1. Why apron is used in laboratory? Answer: An apron is used in the laboratory to protect clothing and skin from accidental spills, splashes of corrosive chemicals, and burns. 2. What is necessity of using goggles? Answer: Safety goggles are essential to protect the eyes from hazardous chemical splashes, corrosive vapors, and flying glass particles during experiments. 3. Why hand-gloves are used? Answer: Hand-gloves are used to protect the hands from direct contact with toxic, corrosive, or irritating chemicals, as well as from thermal burns. 4. What is Zetex gloves? [D. B. 2015] Answer: Zetex gloves are specially designed heat-resistant laboratory gloves made from Zetex fabric (a type of woven silica/fiberglass), used for handling hot objects securely without catching fire. (2) Glass Materials & Apparatus: 1. What is the name of instrument used for boring cork? [Ctg. B. 2015] Answer: The instrument used for boring a cork is called a cork borer. 2. What is cleansing

7. What is meant by TC on volumetric flask? Answer: TC stands for “To Contain,” meaning the apparatus is calibrated to hold the exact specified volume of liquid at a given temperature, but it may not deliver that exact volume when poured. 8. What is meant by T D on pipette? Answer: TD stands for “To Deliver,” meaning the apparatus is calibrated to accurately dispense the stated volume of liquid at the specified temperature. 9. How non-luminous flame is produced in bunsen burner? Answer: A non-luminous (blue) flame is produced when the air hole of the Bunsen burner is fully open, allowing sufficient oxygen to mix with the fuel gas for complete combustion. 10. What is oxidising flame? [Di. B. 2019] Answer: The outer, faint bluish region of the non-luminous Bunsen flame where complete combustion occurs and excess oxygen is present is called the oxidizing flame. 11. What is aqua-regia? Answer: Aqua-regia is a highly corrosive mixture of concentrated hydrochloric acid (HCl) and concentrated nitric acid (HNO3) in a 3:1 molar ratio, capable of dissolving noble metals like gold and platinum. 12. What is hazard symbol? [Syl. B. 2019; Di. B. 2019; D. B. 2016] Answer: A hazard symbol is a uni

Answer: A fire-blanket is made of fire-resistant material and is used to quickly smother and extinguish small fires, especially if a person’s clothing catches fire. 8. What is first aid box or kit? [R. B. 2016; Di. B. 2017; C. B. 2019] Answer: A first aid box is a collection of essential medical supplies and equipment kept in the laboratory to provide immediate initial care for injuries such as cuts, burns, or chemical exposure. Group B: Understanding Based Questions (At a Glance) 1. What are the advantages to use safety glass in lab? [B. B. 2019] Answer: Safety glasses protect the eyes from chemical splashes, caustic fumes, and flying debris during reactions. They provide a physical barrier against irreversible eye damage that could result from accidental spills or glass breakages. 2. What are the advantages to wear gloves in lab? [C. B. 2019] Answer: Wearing gloves acts as a protective shield against direct skin contact with toxic, corrosive, or allergenic chemicals. It also minimizes the risk of absorbing hazardous substances through the skin and protects against minor thermal burns. 3. What are the advantages to use rider in Paul Bunge balance? [J. B. 2017] Answer: The rider in