General Chemistry
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True or False. The K+ ions have octahedral coordination to four C60— molecular ions in K6C60, a fullerene-based superconductor.
By using X-ray crystallography, the molecular structure of a protein may be determined if it can be made to crystallize. Despite being solid, protein crystals also contain a significant quantity of water molecules. For instance, a protein extracted from a fruit crystallizes with a unit cell that has 90° angles and edges that are 6.2×103 pm, 6.2×103 pm, and 2.1×103 pm long. The unit cell has eight molecules. What portion of the unit cell is made up of protein if the molecule has a molecular weight of 1.36×104 and a density of 1.32 g/cm3?
The lithium metal has a body-centered cubic structure when it crystallizes. What is the illustration of its unit cell? Is it possible to draw an electron-dot structure showing the bond between the central atom and its nearest neighboring atom?
Potassium fluoride crystallizes in a cubic unit cell with a single K+ ion in the center and eight F— ions at the corners. Which statement is true regarding the number of positive and negative charges in the unit cell?
Identify the kind of packing for the following
In a 350 mL evacuated flask, a cube-shaped crystal of an alkali metal with an edge length of 0.936 mm was vaporized. The vapor pressure that resulted was 13.7 mmHg at 789 °C. It is well known that the metal has a body-centered cubic structure. Determine the density in g/cm3 of the solid and vapor.
In a 350 mL evacuated flask, a cube-shaped crystal of an alkali metal with an edge length of 0.936 mm was vaporized. The vapor pressure that resulted was 13.7 mmHg at 789 °C. It is well known that the metal has a body-centered cubic structure. What is the identity of the metal?
The edge length of the body-centered cubic unit cell of vanadium is 303 pm. The density and molar mass of V is 6.11 g/cm3 and 50.94 g/mol, respectively. Estimate the value of Avogadro's number.
Potassium crystallizes into a body-centered cubic unit cell with a density of 0.862 g/cm3. Determine the edge length of the cell and radius of the atom in picometers.
The crystal of chromium has a body-centered cubic unit cell. Its edge length is 288 pm. If a unit cell diagonal passes through the center atom, what is the length of the diagonal in pm?
Lithium has body-centered cubic structure and has a density of 0.534 g/mL which is much less than water. This means that it should float on water which has a density of approximately 1 g/mL at room temperature. Calculate the density of Li if the structure was a cubic close-packed structure and identify if it would still float on water.
Consider the unit cell containing Ti, Ca, and O below:
The Ti atoms are in the center, the O atoms are on the face and the Ca atoms are on the corners. Identify the empirical formula of the compound and the oxidation state of Ti.
Calculate the density of Ni metal if it l crystallizes in a face-centered cubic unit cell and has an edge length of 3.524 Å.
Identify the number of chromium atoms in its unit cell if it crystallizes with the body-centered cubic structure.
Identify the number of atoms in a unit cell of chromium.
Calculate the atomic mass of an unknown metal that has a body-centered cubic lattice with a density of 6.11 g/cm3. The edge length of the unit cell is 0.3048 nm.
Calculate the radius of a chromium atom given that it has a body-centered cubic unit cell and a density of 7.19 g/cm3
Calculate the edge length of the unit cell and the density of tungsten given that it has a body-centered unit cell and a radius of 137 pm
Calculate the density of Chromium, if it has an edge length of 2.87 Å using a body-centered cubic unit cell structure
Chromium adopts a body-centered cubic unit cell with a density of 7.19 g/cm3
Identify each of the following:
i. the number of atoms per cm3
ii. the number of unit cells present per cm3
iii. the volume of a unit cell
iv. the edge length (Choose one below)
For the body-centered cubic unit cell, identify each of the following:
i. the number of corner atoms
ii. fraction of each corner atom in the cube
iii. number of body atoms
iv. fraction of each body atom in the cube
v. Total number of atoms inside the cube
An unknown metal is found to have a density of 7.20 g/cm3 and to crystallize in a body-centered cubic lattice. The edge of the unit cell is 0.301 nm. Calculate the atomic mass of the metal.