Answer:
Fe₃Si₇
Explanation:
In order to determine the empirical formula, we have to follow a series of steps.
Step 1: Determine the percent composition
Fe: 46.01%
Si: 53.99%
Step 2: Divide each percentage by the atomic mass of the element
Fe: 46.01/55.85 = 0.8238
Si: 53.99/28.09 = 1.922
Step 3: Divide all the numbers by the smallest one
Fe: 0.8238/0.8238 = 1
Si: 1.922/0.8238 = 2.33
Step 4: Multiply by numbers that make the coefficients whole.
Fe: 1 × 3 = 3
Si: 2.33 × 3 = 7
The empirical formula is Fe₃Si₇.
Answer:
The molecules absorb heat and acquire more kinetic energy.
Explanation:
In a solid, the solids only vibrate about their mean positions but do not translate. When energy is supplied to the molecule in the form of heat, the molecules vibrate faster. Eventually, they acquire sufficient energy to leave their mean positions and translate. Hence the solid crystal collapses.
When ice is heated, water molecules acquire sufficient kinetic energy to translate. The intermolecular bonds are gradually broken in the solid framework as heat is absorbed. The heat required for this is known as the latent heat of fusion.
The temperature remains constant until phase transition is over, then temperature rise resumes.
Answer:
The density of Lithium β is 0.5798 g/cm³
Explanation:
For a face centered cubic (FCC) structure, there are total number of 4 atoms in the unit cell.
we need to calculate the mass of these atoms because density is mass per unit volume.
Atomic mass of Lithium is 6.94 g/mol
Then we calculate the mass of four atoms;
⇒next, we estimate the volume of the unit cell in cubic centimeter
given the edge length or lattice constant a = 0.43nm
a = 0.43nm = 0.43 X 10⁻⁹ m = 0.43 X 10⁻⁹ X 10² cm = 4.3 X 10⁻⁸cm
Volume of the unit cell = a³ = (4.3 X 10⁻⁸cm)³ = 7.9507 X 10⁻²³ cm³
⇒Finally, we calculate the density of Lithium β
Density = mass/volume
Density = (4.6097 X 10⁻²³ g)/(7.9507 X 10⁻²³ cm³)
Density = 0.5798 g/cm³
