A because of the way it looks and how it works
Answer:
A:force times an object displacement
Explanation:
Rarely they can't with just sight. Certain tests or experiments should take place
Answer:

Explanation:
Hello,
In this case, the enthalpy of combustion is understood as the energy released when one mole of fuel, in this case octene, is burned in the presence of oxygen and is computed with the enthalpies of formation of the fuel, carbon dioxide and water as shown below (oxygen is circumvented as it is a pure element):

Thus, since we already know the enthalpy of combustion of the fuel, for carbon and water we have -393.5 and -241.8 kJ/mol respectively, thereby, the enthalpy of combustion turns out:

Best regards.
Answer:
The relevant equation is:
CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂
Explanation:
1 mol of calcium carbonate can react to 2 moles of Hydrochloric acid to produce 1 mol of water, 1 mol of calcium chloride and 1 mol of carbon dioxide.
The formed CO₂ is the reason why you noticed bubbles as the reaction took place