Gravimetric Method

Question 1

What are the two major types of gravimetric methods?

Answer 1

1. Precipitation

2. Volatilization

Question 2

A solid that is made up of particles having diameters that are less than 10^-4 cm.

Answer 2

Colloid

Question 3

True or False.

Precipitates should be made up of small particles for them to be filtered and washed easily.

Answer 3

False.

Precipitates are desirable when it is large.

Question 4

How do precipitates form?

Answer 4

1. Nucleation

2. Particle growth

Question 5

What is the initial process for the formation of a crystal?

Answer 5

Nucleation

Question 6

What process in the formation of precipitates needs a pre-existing crystal structure to start?

Answer 6

Particle growth

Question 7

What do you call the process in which a substance (gas, liquid, or solid) is held on the surface of a solid?

Answer 7

Adsorption

Question 8

What is the drastic but effective way to minimize the effects of adsorption?

Answer 8

Reprecipitation or double precipitation

Question 9

What is the common source of coprecipitation (most likely to cause significant contamination of precipitates)?

Answer 9

Adsorption

Question 10

What type of coprecipitation happens when a compound is trapped within a pocket that is formed during rapid crystal growth?

Answer 10

Occlusion

Question 11

What type of coprecipitation happens when crystals lie close together during growth?

Answer 11

Mechanical entrapment

Question 12

What process happens when a precipitate is formed by the slow generation of a precipitating reagent homogeneously throughout a solution?

Answer 12

Homogenous solution