3. Which of the following items should be in case of an emergency? Eyewash station b) First aid kit c) Fire extinguisher d) All of the above 4. When heating substances in the lab, which of the following precautions should be taken? a) Always heat substances in a closed container b) Keep flammable materials away from heat sources c) Do not pay attention to the heat source d) You can heat anything without checking its safety guidelines

3. The correct answer is d) All of the above. In case of an emergency, it is important to have an eyewash station, first aid kit, and fire extinguisher. These items can help provide immediate medical attention and prevent the spread of fire.<br /><br />4. The correct answer is a) Always heat substances in a closed container. When heating substances in the lab, it is important to take precautions to prevent accidents. Heating substances in a closed container can help prevent the release of harmful fumes and reduce the risk of fire. Additionally, keeping flammable materials away from heat sources is crucial to prevent accidental ignition. It is also important to pay attention to the heat source and follow safety guidelines when heating substances.