# Density

## Trending Questions

**Q.**Henry's law constant for CO2 in water is

1.67×108 Pa at 298 K. Calculate the quantity of CO2 in 500mL of soda water when packed under 2.5 atm CO2 pressure at 298 K.

**Q.**Calculate:

A: Molality of KI if the density of 20% (mass/mass) aqueous KI is 1.202 g mL−1.

B: Molarity of KI if the density of 20% (mass/mass) aqueous KI is 1.202 g mL−1.

C: Mole Fraction of KI if the density of 20% (mass/mass) aqueous KI is 1.202 g mL−1.

**Q.**The number of octahedral void(s) per atom present in a cubic-close-packed structure is: (1) 2 (2) 4 (3) 1 (4) 3

**Q.**

Gold crystallizes in CCP structure. The total number of voids present In $197\mathrm{gms}$ of Gold will be

**Q.**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 (assuming molar mass and atomic radii of iron remains constant with temperature) is:

- 3 (√3)4 (√2)
- 4 (√3)3 (√2)
- (√3) (√2)
- 12

**Q.**

An element (atomic mass 100 g/mol) having bcc structure has a unit cell edge of 400 pm. Then the density of the element is

- 10.376 g/cm
^{3} - 7.289 g/cm
^{3} - 2.144 g/cm
^{3} - 5.188 g/cm
^{3}

**Q.**

A metal has a fcc lattice. The edge length of the 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 = 6.02×1023mol−1)

20 g mol−1

40 g mol−1

30 g mol−1

27 g mol−1

**Q.**The correct order of melting point of 3d transition metals is

- Ti<V<Cr<Mn<Fe<Cu
- Ti<V<Cr>Mn<Fe<Cu
- Ti<V<Cr>Mn<Fe>Cu
- Ti<V>Cr<Mn<Fe>Cu

**Q.**A solution containing 10.2g glycerine per litre is isotonic with a 2 percent solution of glucose. What is the molecular mass of glycerine?

**Q.**200 cm3 of an aqueous solution of a protein contains 1.26 g of the protein. The osmotic pressure of such a solution at 300 K is found to be 2.57×10−3 bar. Calculate the molar mass of the protein.

**Q.**

A metal crystallizes into two cubic phases, FCC and BCC whose unit cell lengths are 3.5 and 3.0 Å respectively. The ratio of densities of FCC and BCC.

**Q.**

Silver crystallizes in fcc lattice. If the edge length of the cell is 4.07×10−8cm and density is 10.5 g cm−3, calculate the atomic mass of silver.

**Q.**

An element with a molar mass of $2.7\times {10}^{-2}$** **$\mathrm{kg}{\mathrm{mol}}^{-1}$ forms a cubic unit cell with an edge length of** **$405pm$. If its density is $2.7\times {10}^{3}$** **$\mathrm{kg}{\mathrm{m}}^{-3}$, the radius of the element is approximately ______ ${10}^{-12}\mathrm{m}$** **(to the nearest integer).

**Q.**

Copper crystallises into a fcc lattice with edge length 3.61×10−8cm. Show that the calculated density is in agreement with its measured value of 8.92 g cm−3

**Q.**

Mole fraction of urea in 900 gram water is 0.05. Density of Solution is 1.2 g/cm^{3}. Find molarity of Solution.

**Q.**A metal crystallises with a F.C.C. lattice. The edge of the unit cell is 408 pm. The diameter of the metal atom is

- 144 pm
- 204 pm
- 288 pm
- 408 pm

**Q.**

Lithium borohydride crystallizes in an orthorhombic system with 4 molecules per unit cell. The unit cell dimensions are a = 6.8Å, b = 4.4Å and C = 7.2Å. If the molar mass is 21.76g. Density of crystal is (gm/cm^{3})

0.67

0.44

0.23

0.096

**Q.**

The unit cell of aluminum is a cube with an edge length of 405 pm. The density of aluminum is $2.70gc{m}^{-3}$. What is the structure of the unit cell of aluminum?

Body-centered cubic cell

Face-centered cubic cell

End-centered cubic cell

simple cubic cell

**Q.**At 25∘C and 760 mm of Hg pressure a gas occupies 600 mL volume. What will be its pressure at a height where temperature is 10∘C and volume of the gas is 640 mL.

**Q.**A swimmer coming out from a pool is covered with a film of water weighing about 18 g. How much heat must be supplied to evaporate this water at 298 K? Calculate the internal energy of vaporization at 298 K.△vapH⊖ for water at 298 K=44.01 kJ mol−1

**Q.**A crystalline solid of a pure substance has a face-centred cubic structure with a cell edge of 400 pm. If the density of the substance in the crystal is 8 gcm−3, then the number of atoms present in 256 g of the crystal is N×1024. The value of N is

**Q.**

Explain how much portions of an atom located at (i) corner and (ii) body centre of a cubic unit cell is part of its neighbouring unit cell.

**Q.**

Calculate the weight of CO_{2 }which occupies a volume of 11.2 dm^{3 } at STP.

**Q.**When heated above 916∘C, iron changes its BCC crystalline form to FCC without the change in the radius of atom. The ratio of density of the crystal before heating and after heating is (Given : √3=1.73 and √2=1.41):

- 1.069
- 1.231
- 0.725
- 0.917

**Q.**In the face-centred cubic lattice structure of gold the closest distance between gold atoms is: ('a' being the edge length of the cubic unit cell)

- a√2
- a2√2
- 2√2
- a√2

**Q.**What type of defect can arise when a solid is heated?

**Q.**

A compound XY crystallizes in BCC lattice with a unit cell edge length of 480 pm. If the radius of Y^{−} is 225 pm. What will be the radius of X^{+}

$225\mathrm{pm}$

$255\mathrm{pm}$

$127.5\mathrm{pm}$

$190.68\mathrm{pm}$

**Q.**6 : 6 coordination number of NaCl changes to 8 : 8 coordination on:

- applying high pressure
- increase in temperature
- both (A) and (B)
- no effect on coordination

**Q.**calculate the number of formula units of a crystal AB, having Cscl type structure in 240 gm.The unit cell edge lengthof AB is 200 pm and density of crystal is 6gm/cc.

**Q.**

How is the relative vapor density of a gas related to the relative molecular mass of the gas?