7. The molar mass of pottasium dichromate(K2Cr2O7) = 294 g.
<h3>Changes can occur to the physical properties of a substance, but the chemical composition of the substance remains the same.</h3>
Explanation:
A physical change can not change the chemical makeup of a substance. If it did, it would be considered a chemical change. It can, however, be physically changed.
Answer: This law is sometimes referred to as the 'Avogadro's Hypothesis' or 'Avogadro's Principle'. This is an experimnetal gas law that is relating to the volume of gas to the amount of substance of gas that is present to the state. This law also states that ''Equal volumes of all gases, at the same temp. and pressure, have the equal amount of molecules.''.
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Answer:
ΔH°_rxn = -195.9 kJ·mol⁻¹
Explanation:
4NH₃(g) + 3O₂(g) ⟶ 2N₂(g) +6H₂O(g)
ΔH°_f/(kJ·mol⁻¹): -45.9 0 0 -241.8
The formula relating ΔH°_rxn and enthalpies of formation (ΔH°_f) is
ΔH°_rxn = ΣΔH°_f(products) – ΣΔH°_f(reactants)
ΣΔH°_f(products) = -6(241.8) = -1450.8 kJ
ΣΔH°_f(reactants) = -4(45.9) = -183.6 kJ
ΔH°_rxn = (-1450.8 + 183.6) kJ = -1267.2 kJ
