Answer:
True => ΔH°f for C₆H₆ = 49 Kj/mole
Explanation:
See Thermodynamic Properties Table in appendix of most college level general chemistry texts. The values shown are for the standard heat of formation of substances at 25°C. The Standard Heat of Formation of a substance - by definition - is the amount of heat energy gained or lost on formation of the substance from its basic elements in their standard state. C₆H₆(l) is formed from Carbon and Hydrogen in their basic standard states. All elements in their basic standard states have ΔH°f values equal to zero Kj/mole.
Answer: Matter cannot be created or destroyed
Explanation: Balanced equations are set equations we cannot change one element or compound in the equation without changing the entire equation. So balanced equation show the conservation of mass because while other substances may be formed from the synthesis or decomposition of compounds new elements are never introduced and are not created out of thin air :)
Answer:
c) hereditary
Explanation:
This means that if your parents had one eye colour, you'll most likely have the same one because you share the same genes, and it's passed down to you.
Answer:
25 possibly
Explanation:
I'm not too sure about this, but sodium oxide is Na2O, 2 sodium and 1 oxygen, so 12.5g * 2 is 25
If someone else comes up with a more convincing argument listen to them
