You could use another word for change can be variable witch means change and if you times the one two more times then you would get four because two time two would be four and times the one would be four.
False Alkaline earth metals is group 2
Answer:
ΔH = +155.6 kJ
Explanation:
The Hess' Law states that the enthalpy of the overall reaction is the sum of the enthalpy of the step reactions. To do the addition of the reaction, we first must reorganize them, to disappear with the intermediaries (substances that are not presented in the overall reaction).
If the reaction is inverted, the signal of the enthalpy changes, and if its multiplied by a constant, the enthalpy must be multiplied by the same constant. Thus:
N₂(g) + O₂(g) → 2NO(g) ΔH = +180.7 kJ
2NO(g) + O₂(g) → 2NO₂(g) ΔH = -113.1 kJ
2N₂O(g) → 2N₂(g) + O₂(g) ΔH = -163.2 kJ
The intermediares are N₂ and O₂, thus, reorganizing the reactions:
N₂(g) + O₂(g) → 2NO(g) ΔH = +180.7 kJ
NO₂(g) → NO(g) + (1/2)O₂(g) ΔH = +56.55 kJ (inverted and multiplied by 1/2)
N₂O(g) → N₂(g) + (1/2)O₂(g) ΔH = -81.6 kJ (multiplied by 1/2)
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N₂O(g) + NO₂(g) → 3NO(g)
ΔH = +180.7 + 56.55 - 81.6
ΔH = +155.6 kJ
Answer:
See explanation
Explanation:
1 mole of a gas occupies 22.4 L
x moles occupies 16.8 L
x = 1 mole * 16.8 L/22.4 L
x = 0.75 moles
number of moles = mass/molar mass
mass = number of moles * molar mass
mass = 0.75 moles * 30.01 g/mol = 22.5075 g = 2.25 * 10^1 g
the coefficient of the scientific notation answer = 2.25
the exponent of the scientific notation answer = 1
significant figures are there in the answer = 6
the right most significant figure in the answer = 3
2.
number of moles = 12.5g/38g/mol = 0.3289 moles
1 mole occupies 22.4 L
0.3289 moles occupies 0.3289 moles * 22.4 L/1 mole
= 7.36736 L = 7.36736 * 10^0 L= 7.37 * 10^0 L
the coefficient of the scientific notation answer =7.37
the exponent of the scientific notation answer = 0
significant figures are there in the answer = 6
the right most significant figure in the answer= 3
