Answer:
Volume of carbon dioxide is 428.23 L.
Explanation:
Below is the chemical reaction or chemical equation for the combustion of hydrocarbons such as undecane into carbon dioxide.

Here, undecane is in liquid form that reacts with gaseous oxygen (combustion) and produces carbon dioxide and water as a product in the gaseous form.
The molar mass of undecane = 

From the equation, it can be seen that 1 mole of undecane produces 11 moles of carbon dioxide. Therefore, 1.66 mol will produce 18.26 mol of carbon dioxide.
Now find the volume of 18.26 mol of carbon dioxide when the temperature is 13 degrees Celsius and pressure is 1 atm.



Answer:
Because it can cause health problems or injuries to our sense organs.
Explanation:
Chemicals in the laboratory are made up of different constituents, which may be dangerous or injurious to health. This is the reason why safety measures or precautions have to be taken when working in the laboratory. One of those safety measures is that "one should never use taste, touch, or smell to identify an unknown chemical".
This is so because a chemical that is unknown amounts to the fact that what such chemical contains is unknown, hence, the chemical might have the ability to cause harm or injuries to the sense organ. For example, a conc. acid that is tasted will burn the tongue etc.
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