Answer:
THE SOUND TRAVELS FASTER IN SOLIDS BECAUSE ITS MOLECULES ARE CLOSE TO EACH OTHER WHILE LIQUIDS MOLECULES ARE NOT TIGHT AS OF SOLID AND IN GAS THE MOLECULES ARE FREE
I think it's called "<span>combustion." are there any answer choices though?
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<span>Water is considered as a polar molecule because its electrons has an uneven distribution. It has a partial negative charge and a partial positive charge on both ends of the molecule. </span>I hope my answer has come to your help. God bless and have a nice day ahead!
Hey there!
Great question;)
Answer:Physical change
Explanation: When sugar mixes with water, at the end, the chemical formulas are the same. Nothing has changed!
I hope this helps;)
Answer:
-125 kJ
Explanation:
You calculate the energy required to break all the bonds in the reactants. Then you subtract the energy to break all the bonds in the products.
H₂C=CH₂ + H₂ ⟶ H₃C-CH₃
Bonds: 4C-H + 1C=C 1H-H 6C-H + 1C-C
D/kJ·mol⁻¹: 413 612 436 413 347
The formula relating ΔHrxn and bond dissociation energies (D) is
ΔHrxn = Σ(Dreactants) – Σ(Dproducts)
(Note: This is an exception to the rule. All other thermochemical reactions are “products – reactants”. With bond energies, it’s “reactants – products”. The reason comes from the way we define bond energies.)
<em>For the reactant</em>s:
Σ(Dreactants) = 4 × 413 + 1 × 612 + 1 × 436 = 2700 kJ
<em>For the products:</em>
Σ(Dproducts) = 6 × 413 + 1 × 347 = 2825 kJ
<em>For the system</em>
:
ΔHrxn = 2700 - 2825 = -125 kJ
