8)
1 answer:
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Explanation:
Given parameters:
Mass of sample = 235g
Molecular mass of sample = 128.1g
Empirical formula = CH₂O
Unknown:
Mass of each element in the sample = ?
Solution:
To solve this problem, we must know that the empirical formula of any compound is the simplest ratio of the atoms it contains. This is not the true formula of the compound.
Molecular formula = (Empirical formula)ₙ
Let us find the molecular mass of the sample;
CH₂O = 12 + 2(1) + 16 = 30g
128.1 = (30)n
n = 4
The molecular formula of the compound is; (CH₂O)₄ = C₄H₈O₄
Now to find the grams of each element in the sample;
Express the molecular mass of each element and that of the compound as a fraction and multiply with the given mass;
For C;
= 88.06g
H; = 14.68g
O: = 117.41g
learn more:
Mass composition brainly.com/question/3018544
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<u>Answer:</u> The correct answer is Aufbau principle.
<u>Explanation:</u>
Pauli exclusion principle states that no two electrons with in an atom can have all four quantum numbers same.
Heisenberg principle states that it is impossible to measure with high precision the value of momentum and position of an electron.
Aufbau principle states that the electron will occupy the lowest energy level first before occupying the higher energy levels.
Schrodinger equation is used to find the allowed energy levels of quantum mechanical systems of an electron.
Chromium is the 24th element of the periodic table and its electronic configuration must be written as:
But the actual configuration for this is
This configuration is an exception to Aufbau's principle because half filled sub-levels is more stable than other configurations.
The actual configuration has half filled 'd' and 's' sub-levels but the expected configuration had fully filled 's' orbital and partially filled 'd' orbital.
Thus, actual configuration is accepted for chromium atom.
Hence, the correct answer is Aufbau's principle.