Ask Questions, Get Answers

Want to ask us a question? Click here
Browse Questions
0 votes

Ice crystallizes in hexagonal lattice. At the low temperature at which structure was determined the lattice constants were $a = 4.53A^{\large\circ}$ and C = $a = 7.41A^{\large\circ}$ .Calculate the no. of $H_2O$ molecules present in a unit cell. (Density of ice = 0.92g/cm)


Can you answer this question?

1 Answer

0 votes
Volume of unit cell V = Area of $base\times height$
$=2\times\large\frac{\sqrt3}{4}a^2\times c$
Mass of unit cell = $V\times\rho$
Let there are n effective water molecules in the given unit cell. Then n times the mass of each water molecule would be the mass of unit cell.
$\therefore 1.21\times10^{-22} = n\times\large\frac{18}{6.023\times10^{23}}$
$\therefore n =4$
Hence answer is (c)
answered Feb 24, 2014 by sharmaaparna1

Related questions

Ask Question
student study plans
JEE MAIN, CBSE, AIPMT Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App