Home
Class 12
PHYSICS
When examining the suspended gamboge dro...

When examining the suspended gamboge droplets under a microscope, their average numbers in the layers separated by the distance `h = 40 mu m`, and their density exceeds that of the surrounding fluid by `Delta rho = 0.20 g//cm^3`. Find Avogadro's number from these data.

Text Solution

Verified by Experts

Here `F = (pi)/(6) d^3 Delta rho g = (RT 1n eta)/(N_a h)` or `N_a = (6 RT 1n eta)/(pi d^3 g Delta rho h)`
In the problem, `(eta)/(eta_0) = 1.39` here
`T = 290 K, eta = 2, h = 4 xx 10^-5 m, d = 4 xx 10^-7 m, g = 9.8 m//s^2, Delta rho = 0.2 xx 10^3 kg//m^2`
and `R = 8.31 J//K`
Hence, `N_a = (6 xx 8.31 xx 290 xx 1 n 2)/(pi xx 64 xx 9.8 200 xx 4) xx 10^26= 6.36 xx 10^23 "mole"^-1`.
Promotional Banner

Topper's Solved these Questions

  • THERMODYNAMICS AND MOLECULAR PHYSICS

    IE IRODOV, LA SENA & SS KROTOV|Exercise The Second Law Of Thermodynamics - Entropy|47 Videos

  • THERMODYNAMICS AND MOLECULAR PHYSICS

    IE IRODOV, LA SENA & SS KROTOV|Exercise Liquids Capillary Effects|25 Videos

  • THERMODYNAMICS AND MOLECULAR PHYSICS

    IE IRODOV, LA SENA & SS KROTOV|Exercise The First Law Of Thermodynamics - Heat Capacity|36 Videos

  • PHYSICAL FUNDAMENTALS OF MECHANICS

    IE IRODOV, LA SENA & SS KROTOV|Exercise Relativistic Mechanics|49 Videos

Similar Questions

Explore conceptually related problems

By X-ray diffraction it is found tht nickel ("at mass"=59g "mol"^(-1)) , crystakkuzes with ccp. The edge length of the unit cell is 3.5 Å . If density of Ni crystal is 9.0g//cm^(3) , then value of Avogadro's number from the data is:

Calculate the value of Avogadro number from the internuclear distance of adjacent ions in NaCl, 0.282 nm and the density of solid NaCl is 2.17xx10^(3)kg//m^(3) . A unit cell contains 4 NaCl formula units.

Density of a unit cell is same as the density of the substance. If the density of the substance is known, number of atoms or dimensions of the unit cell can be calculated . The density of the unit cell is related to its mass(M), no. of atoms per unit cell (Z), edge length (a in cm) and Avogadro number N_A as : rho = (Z xx M)/(a^3 xx N_A) The number of atoms present in 100 g of a bcc crystal (density = 12.5 g cm^(-3)) having cell edge 200 pm is

Density of a unit cell is same as the density of the substance. If the density of the substance is known, number of atoms or dimensions of the unit cell can be calculated . The density of the unit cell is related to its mass(M), no. of atoms per unit cell (Z), edge length (a in cm) and Avogadro number N_A as : rho = (Z xx M)/(a^3 xx N_A) A metal X (at. mass = 60) has a body centred cubic crystal structure. The density of the metal is 4.2 g cm^(-3) . The volume of unit cell is

Density of a unit cell is same as the density of the substance. If the density of the substance is known, number of atoms or dimensions of the unit cell can be calculated . The density of the unit cell is related to its mass(M), no. of atoms per unit cell (Z), edge length (a in cm) and Avogadro number N_A as : rho = (Z xx M)/(a^3 xx N_A) An element crystallizes in a structure having a fcc unit-cell an edge 100 pm. If 24 g of the element contains 24 xx 10^(23) atoms, the density is

A syringe is filled with water. Its volume is V_(0)=40cm^(2) and cross section of its interior is A =8cm^(2) . The syrings is held vertically such that its nozzle is at the top, and its piston is pushed up with constant speed. Mass of the piston is M=50 g and the water is ejected at a speed of u_(0)=2m//s . cross section of the stream of water at the nozzle is a=2mm^(2) . Neglect friction and take the density of water to be rho=10^(3)kg//m^(3) (a) Find the speed of the piston (b) Find the total work done by the external agent in emptying the syringe.

When an object moves through a fluid, as when a ball falls through air or a glass sphere falls through water te fluid exerts a viscous foce F on the object this force tends to slow the object for a small sphere of radius r moving is given by stoke's law, F_(w)=6pietarv . in this formula eta in the coefficient of viscosity of the fluid which is the proportionality constant that determines how much tangential force is required to move a fluid layer at a constant speed v, when the layer has an area A and is located a perpendicular distance z from and immobile surface. the magnitude of the force is given by F=etaAv//z . For a viscous fluid to move from location 2 to location 1 along 2 must exceed that at location 1, poiseuilles's law given the volumes flow rate Q that results from such a pressure difference P_(2)-P_(1) . The flow rate of expressed by the formula Q=(piR^(4)(P_(2)-P_(1)))/(8etaL) poiseuille's law remains valid as long as the fluid flow is laminar. For a sfficiently high speed however the flow becomes turbulent flow is laminar as long as the reynolds number is less than approximately 2000. This number is given by the formula R_(e)=(2overline(v)rhoR)/(eta) In which overline(v) is the average speed rho is the density eta is the coefficient of viscosity of the fluid and R is the radius of the pipe. Take the density of water to be rho=1000kg//m^(3) Q. If the sphere in previous question has mass of 1xx10^(-5)kg what is its terminal velocity when falling through water? (eta=1xx10^(-3)Pa-s)

When an object moves through a fluid, as when a ball falls through air or a glass sphere falls through water te fluid exerts a viscous foce F on the object this force tends to slow the object for a small sphere of radius r moving is given by stoke's law, F_(w)=6pietarv . in this formula eta in the coefficient of viscosity of the fluid which is the proportionality constant that determines how much tangential force is required to move a fluid layer at a constant speed v, when the layer has an area A and is located a perpendicular distance z from and immobile surface. the magnitude of the force is given by F=etaAv//z . For a viscous fluid to move from location 2 to location 1 along 2 must exceed that at location 1, poiseuilles's law given the volumes flow rate Q that results from such a pressure difference P_(2)-P_(1) . The flow rate of expressed by the formula Q=(piR^(4)(P_(2)-P_(1)))/(8etaL) poiseuille's law remains valid as long as the fluid flow is laminar. For a sfficiently high speed however the flow becomes turbulent flow is laminar as long as the reynolds number is less than approximately 2000. This number is given by the formula R_(e)=(2overline(v)rhoR)/(eta) In which overline(v) is the average speed rho is the density eta is the coefficient of viscosity of the fluid and R is the radius of the pipe. Take the density of water to be rho=1000kg//m^(3) Q. Which of the following may be concluded from the information in the passage?

A particle suspended from a vertical spring oscillates 10 times per second. At the highest point of oscillation , the spring becomes upstretched . Find the speed when the spring is stretched by 0.20 cm . (Take , g = pi^(2) m//s^2)

Light with wavelength lambda = 0.55 mu m from a distant point source falls normally on the surface of a glass wedge. A fringe pattern whose neighbouring maxima on the surface of the wedge are separated by a distance Delta x = 0.21 mm is observed in reflected light. Find: (a) the angle between the wedge faces, (b) the degree of light monochromatism (Delta lambda//lambda) if the fringes disappear at a distance l ~~ 1.5 cm from the wedge's edge.

IE IRODOV, LA SENA & SS KROTOV-THERMODYNAMICS AND MOLECULAR PHYSICS-Kinetic Theory Of Gases
  1. Making use of the Maxwell distribution function, calculate the number ...

    Text Solution

    |

  2. Using the Maxwell distribution function, determine the pressure extert...

    Text Solution

    |

  3. Making use of the Maxwell distribution function, find lt lt 1//v gt gt...

    Text Solution

    |

  4. A gas consists of molecules of mass m and is at a temperature T. Maki...

    Text Solution

    |

  5. What fraction of monatomic molecules of a gas a in a thermal equilibri...

    Text Solution

    |

  6. What fraction of molecules in a gas at a temperature T has the kinetic...

    Text Solution

    |

  7. The velocity distribution of molecules in a beam coming out of a hole ...

    Text Solution

    |

  8. An ideal gas consisting of molecules of mass m with concentration n ha...

    Text Solution

    |

  9. From the conditions of the foregoing problem find the number of molec...

    Text Solution

    |

  10. Find the force exerted on a particle by a uniform field if the concent...

    Text Solution

    |

  11. When examining the suspended gamboge droplets under a microscope, thei...

    Text Solution

    |

  12. Suppose that eta0 is the ratio of the molecular concentration of hydro...

    Text Solution

    |

  13. A tall vertical vessel contains a gas composed of two kinds of molecul...

    Text Solution

    |

  14. A very tall vertical cylinder contains carbon dioxide at a certain tem...

    Text Solution

    |

  15. A very tall vertical cylinder contains a gas at a temperature true T. ...

    Text Solution

    |

  16. A horizontal tube of length l =100 cm closed form both ends is displac...

    Text Solution

    |

  17. Find the mass of a mole of colloid particles if during their centrifug...

    Text Solution

    |

  18. A horizontal tube with closed ends is rotated with a constant angular ...

    Text Solution

    |

  19. The potential energy of gas molecules in a certain certral field depen...

    Text Solution

    |

  20. From the conditions of the foregoing problem find : (a) the number o...

    Text Solution

    |