Question

28. when foreign ions get trapped 1 point
in growing crystal is called
O A. Inclusion
O B. Mechanical Entrapment
O C. Surface adsorption
O D.Occlusion​

Answer 1

Answer:

$surface absorption$

Answer 2

Answer:

Option D. Occlusion

Explanation:

• Gravimetric analysis is an analytical method that is often used to determine the amount of an analyte (the ion to be analyzed) by measuring the mass.

• Gravi + measure = weigh + measure

• Coprecipitation refers to anything unwanted that precipitates along with the desired thing i.e. simultaneous precipitation of more than one compound from a solution. Coprecipitation occurs to some  in every gravimetric analysis.

• Inclusion refers to the crystallographic defect. When a positive error occurs it increases the weight of ppt while a negative error occurs, it decreases the weight of ppt.

Thus Option A. is incorrect.

• Surface adsorption refers to the surface adhesion of impurities on ppt.

Thus Option C. is incorrect.

• Mechanical entrapment represents when small amount of solution is entrapped.

Thus Option B. is incorrect.

• Occlusion refers to the type of coprecipitation in which impurities or foreign ions are trapped within the counter ion layer in the growing crystal.

Thus Option D. Occlusion is correct.

Hence when foreign ions get trapped in growing crystal is called occlusion.