NEET
Chemistry

Density Packing Fraction

Medium Priority
Consistency: 45%
Weightage: 9 / 20 Yrs

High-Yield Trend

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2023
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2022
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2018
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2013
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2012
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2010
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2009
3
2008
1
2007

Questions
11 MCQs

01
PYQ 2007
easy
chemistry ID: neet-200

The fraction of total volume occupied by the atoms present in a simple cube is:

1. \pi 6

2. \pi 32

3. \pi 42

4. \pi 4

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02
PYQ 2008
easy
chemistry ID: neet-200

If the lattice parameter for a crystalline structure is 3.6 Å, then the atomic radius in fcc crystal is:

1. 1.81 Å

2. 2.10 Å

3. 2.92 Å

4. 1.27 Å

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03
PYQ 2008
easy
chemistry ID: neet-200
Which of the following statements is not correct?
1. The fraction of the total volume occupied by
die atoms in a primitive cell is 0.48
2. Molecular solids are generally volatile
3. The number of carbon atoms in a unit
cell of a diamond is 8
4. The number of Bravais lattices in which a
crystal can be categorized is 14

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04
PYQ 2008
easy
chemistry ID: neet-200
The percentage of free space in a body-centered cubic unit cell is:

1. 30%
2. 32%
3. 34%
4. 28%
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05
PYQ 2009
easy
chemistry ID: neet-200
Sodium has body-centered packing. The distance between the two nearest atoms is 3.7 Å. The lattice parameter is:
1. 6.8 Å
2. 4.3 Å
3. 3.0 Å
4. 8.5 Å
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06
PYQ 2010
easy
chemistry ID: neet-201

AB crystallizes in a body-centered cubic lattice with edge length 'a' equal to 387 pm. The distance between two oppositely charged ions in the lattice is:

1. 335 pm

2. 250 pm

3. 200 pm

4. 300 pm

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07
PYQ 2012
easy
chemistry ID: neet-201

A metal crystallizes with a fcc lattice. The edge of the unit cell is 408 pm. The diameter of the metal atom is:

1. 288 pm

2. 408 pm

3. 144 pm

4. 204 pm

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08
PYQ 2013
easy
chemistry ID: neet-201
A metal has a fcc lattice. The edge length of the unit cell is 404 pm. The density of the metal is 2.72 g cm–3. The molar mass of the metal is:
(NA Avogadro's constant = 6.02 \times 1023 mol–1)
1. 30 g mol–1
2. 27 g mol–1
3. 20 g mol–1
4. 40 g mol–1
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09
PYQ 2018
medium
chemistry ID: neet-201

Iron exhibits bcc structure at room temperature. Above 900 °C, it transforms to fcc structure. The ratio of density of iron at room temperature to that at 900 °C is:

(Molar mass and atomic radii of iron remain constant with temperature)

1. 32

2. 4332

3. 3342

4. 12

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10
PYQ 2022
easy
chemistry ID: neet-202
Copper crystallises in fcc unit cell with a cell edge length of cm. The density of copper is . The atomic mass of copper is:

1. 65 u
2. 63.1 u
3. 31.55 u
4. 60 u
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11
PYQ 2023
medium
chemistry ID: neet-202
A compound is formed by two elements A and B. The element B forms cubic close-packed structure and atoms of A occupy 1/3 of tetrahedral voids. If the formula of the compound is then the value of x+y is in option
1. 2
2. 5
3. 4
4. 3
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