Thus problem is providing us with the mass of iron (III) oxide as 12.4 g so the moles are required and found to be 0.0776 mol after the calculations:
<h3>Mole-mass relationships:</h3>
In chemistry, we use mole-mass relationships in order to calculate grams from moles and vice versa. In this case, since we are given the mass of iron (III) oxide as 12.4 g one can calculate the moles by firstly quantifying its molar mass:

Then, we prepare a conversion factor in order to cancel out the grams and thus, get moles:

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Answer:
Problem: The density of ethanol is 0.789 g/cm3 .What is its density in pounds per cubic inch ( lb/in3)?. Based on our data, ... 1 in = 2.54 cm. density = 0 . 789 g ...
Explanation:
a. Hydrogen
Hydrogen has a line at 410 nm.
Mercury has a line at 405 nm.
Sodium and neon have no lines near 412 nm.
Answer:
The number of moles of benzaldehyde = 0.0253 moles
Explanation:
The molecular formula of benzaldehyde is C₇H₆O
Its molecular mass is calculated from the atomic masses of the constituent atoms.
C = 12.0 g: H = 1.0 g; O = 16.0 g
Molecular mass = ( 12 * 7) + (1 * 6) + (16 * 1) = 106.0 g/mol
Number of moles of substance = mass of substance/ molar mass of the substance
mass of benzaldehyde = 2.68; molar mass = 106.0 g/mol
Number of moles of benzaldehyde = 2.68 g/ 106 g/mol = 0.0253 moles
Therefore, the number of moles of benzaldehyde = 0.0253 moles
Calcium is used to isolate Rb from molten RbX because calcium has a smaller atomic radius than rubidium.
A chemical element's atomic radius, which is typically the average or typical distance between the nucleus's core and the outermost isolated electron, serves as a gauge for the size of an atom. There are numerous non-equivalent definitions of atomic radius since the border is not a clearly defined physical entity. Van der Waals radius, ionic radius, metallic radius, and covalent radius are the four most frequently used definitions of atomic radius. Atomic radii are typically measured in a chemically bound condition since it is challenging to isolated individual atoms in order to measure their radii individually.
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