The values of observed and calculated molecular weights of calcium nitrate are respectively `65.6` and 164. The degree of dissociation of calcium nitrate will be:

Options

A. 0.25
B. 0.5
C. 0.75
D. 0.6

Answer

C

Explanation

For `Ca(NO_(3))_(2) : i = "normal molar Mass"/"exp. molar Mass"`
`Ca(NO_(3))_(2)=Ca^(2+) + 2NO_(3)^(-)`
(x = 1) (y = 2)
`i = prop (x + y-1) + 1 = prop (1+2-1) +1=2 prop + 1`
`:. 164/65.6 = 1 + 2 alpha :. alpha=0.75 or 75%`