Answer:
Large-scale natural disasters
Explanation:
The emergency situation that rescue workers could be in that would make it difficult for them to get energy to their electrical devices is "Large-scale natural disasters"
Large-scale natural disasters are very destructive and devastating. Their impact and effect can range from destruction of infrastructures, properties, social amenities and even ecosystems. When such disasters break out, they destroy things and which leads to difficulty in accessing certain amenities. Rescue workers even find it difficult to access energy for their electrical devices - because there is power outage.
Some of these large-scale natural disasters are earthquakes, tornadoes, hurricanes, floods, etc.
Answer: Th enthalpy of combustion for the given reaction is 594.244 kJ/mol
Explanation: Enthalpy of combustion is defined as the decomposition of a substance in the presence of oxygen gas.
W are given a chemical reaction:



To calculate the enthalpy change, we use the formula:

This is the amount of energy released when 0.1326 grams of sample was burned.
So, energy released when 1 gram of sample was burned is = 
Energy 1 mole of magnesium is being combusted, so to calculate the energy released when 1 mole of magnesium ( that is 24 g/mol of magnesium) is being combusted will be:

c is the answer a benzene
Answer:
Vinegar is acidic => acetic acid (HC₂H₃O₂)
Explanation:
Vinegar consists of acetic acid (HC₂H₃O₂), water and trace amounts of other chemicals, which may include flavorings. The concentration of the acetic acid is variable. Distilled vinegar contains 5-8% acetic acid.