Answer:
ΔH⁰(11.4g NH₄NO₃) = -30.59Kj (4 sig. figs. ~mass of NH₄NO₃(s) given) (exothermic)
Explanation:
3NH₄NO₃(s) + C₁₀H₂₂(l) + 14O₂(g) => 3N₂(g) + 17H₂O(g) + 10CO₂(g)
ΔH⁰(f): 3(-365.6)Kj 1(-301)Kj 14(0)Kj 3(0)Kj 17(-241.8)Kj 10(-393.5)Kj
= -1096.8Kj = -301Kj = 0Kj = 0Kj = -4110.6Kj = -3930.5Kj
ΔHₙ°(rxn) = ∑
(ΔH˚(f)products) - ∑(ΔH˚(f)reactants)
= [3(0)Kj + 17(-241.8)Kj + (-393.5)Kj] - [(-(1096.8)Kj + (-301)Kj + (0)Kj]
= [-(8041.1) - (-1397.8)]Kj
= -6643.3Kj (for 3 moles NH₄NO₃ used in above equation)
∴ Standard Heat of Rxn = -6643.3Kj/3moles = -214.8Kj/mole NH₄NO₃(s)
ΔH°(rxn for 14.11g NH₄NO₃(s)) = (11.4g/80.04g·mol⁻¹)(-214.8Kj/mol) = 30.5937Kj ≅ 30.59Kj (4 sig. figs. ~mass of NH₄NO₃(s) given)
The question is incomplete, the complete question is:
Which statements are consistent with Dalton's atomic theory as it was originally stated? Why?
a. Sulfur and oxygen atoms have the same mass.
b. All cobalt atoms are identical.
c. Potassium and chlorine atoms combine in a 1:1 ratio to form potassium chloride.
d. Lead atoms can be converted into gold.
<u>Answer: </u>The correct options are b) and c).
<u>Explanation:</u>
Some of the postulates of Dalton's atomic theory are:
- All matter is made of very tiny particles called atoms that participate in chemical reactions
- Atoms are indivisible particles that cannot be created or destroyed in a chemical reaction
- Atoms of a given element are identical in mass and chemical properties
- Atoms of different elements have different masses and chemical properties.
- Atoms combine in the ratio of small whole numbers to form compounds.
- The relative number and kinds of atoms are constant in a given compound.
For the given options:
<u>For a:</u>
The statement is inconsistent with the theory as no two elements can have the same mass. Only atoms of the same element can have the same mass.
This is consistent with the theory as atoms of the same element are identical.
This is consistent with the theory as atoms combine in a simple whole number ratio.
The statement is inconsistent with the theory as atoms of one element cannot be changed to atoms of other element.
Hence, the correct options are b) and c).
Answer:
Extraction of aluminium
Aluminium ore is called bauxite . The bauxite is purified to produce aluminium oxide, a white powder from which aluminium can be extracted. The extraction is done by electrolysis. The ions in the aluminium oxide must be free to move so that electricity can pass through it.
Answer:
Palms and other small trees
