The correct answer is C. Magnetic domains must come in pairs one north one south. I took the test.
Correct Answer: <span>They have small differences in electronegativity (statement 3)
Reason:
The nature of chemical bond between atoms is primarily driven by the electronegativity difference between constituent atoms. If electronegativity difference between constituent atoms is significantly higher, ionic bond formation is preferred. On other hand, low difference in electronegativity values, favours formation of covalent bond.
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Answer:
Explanation:
Assume the reaction is the combustion of propane.
Word equation: propane plus oxygen produces carbon dioxide and water
Chemical eqn: C₃H₈(g) + O₂(g) ⟶ CO₂(g) + H₂O(g)
Balanced eqn: C₃H₈(g) + 5O₂(g) ⟶ 3CO₂(g) + 4H₂O(g)
(a) Table of enthalpies of formation of reactants and products
(b)Total enthalpies of reactants and products
ΔᵣH° is negative, so the reaction is exothermic.
The chemical formula for ammonia is NH3. So first, you need to find the molar mass of ammonia (how many grams in one mole).
N=14g
H3=3g
So one mole of NH3 is 17 grams, you can divide 82.9 grams by 17 grams to find the number of molecules. The answer should be 4.876 moles (molecules) of ammonia. Hope this helps!
