Answer:
0.4694 moles of CrCl₃
Explanation:
The balanced equation is:
Cr₂O₃(s) + 3CCl₄(l) → 2CrCl₃(s) + 3COCl₂(aq)
The stoichiometry of the equation is how much moles of the substances must react to form the products, and it's represented by the coefficients of the balanced equation. So, 1 mol of Cr₂O₃ must react with 3 moles of CCl₄ to form 2 moles of CrCl₃ and 3 moles of COCl₂.
The stoichiometry calculus must be on a moles basis. The compounds of interest are Cr₂O₃ and CrCl₃. The molar masses of the elements are:
MCr = 52 g/mol
MCl = 35.5 g/mol
MO = 16 g/mol
So, the molar mass of the Cr₂O₃ is = 2x52 + 3x35.5 = 210.5 g/mol.
The number of moles is the mass divided by the molar mass, so:
n = 49.4/210.5 = 0.2347 mol of Cr₂O₃.
For the stoichiometry:
1 mol of Cr₂O₃ ------------------- 2 moles of CrCl₃
0.2347 mol of Cr₂O₃----------- x
By a simple direct three rule:
x = 0.4694 moles of CrCl₃
Answer:
not valid
Explanation:
Expert judgment is a useful validation method to verify the reliability of an investigation that is defined as “an informed opinion of people with experience in the subject, who are recognized by others as qualified experts in it, and who can give information, evidence, judgments and assessments ”
After submitting an instrument for comparison to the consultation and expert opinion, it must meet two quality criteria: validity and reliability. The validity of content is often established based on two situations, one that concerns the design of a test and the other, the validation of an instrument subject to translation and standardization procedures to adapt it to different cultural meanings. It is here that the task of the expert becomes a fundamental task to eliminate irrelevant aspects, incorporate those that are essential and / or modify those that require it.
Answer:
1. 1568 J
2. 0 J
3. 1176 J
Explanation:
PE = mgh
(PE = Potential Energy) = (m = mass)(g = gravitational force which is 9.8)(h = height)
1. (3)(9.8)(20) = 1568 J
2. PE = (3)(9.8)(0) = 0 J
3. (5)(9.8)(24) = 1176 J
They both have two electron shells. Period indicates number of shells.
