Sublimation

Q.

When does carbon-di-oxide become solid?

Q. A mixture of naphthalene and benzoic acid can be separated by?

1. Chromatography
2. Fractional crsytallisation
3. Sublimation
4. Distillation

Q.

Explain the separation techniques involved in the separations of constituents in gunpowder. What types of reactions are involved in the explosion of gunpowder?

Q. What happens when Epsom salt is heated?

1. $MgS{O}_4.H_{2}O$
2. $MgO$
3. $MgS{O}_4$
4. $S{O}_3$

Q. maximum no of elements that can be placed in 7th period

Q. The solid state formed from gaseous state on cooling is called:

1. sublimation
2. compound
3. sublimate
4. None of the above

Q.

Assign reason for the following

Naphthalene balls disappear when kept in air for few days.

Q. Sublimation is a process in which a solid:

1. changes into vapours
2. changes into liquid form
3. none of the above
4. changes into another allotropic form

Q. Pure iodine can be obtained by the process of ______________ .

1. separating funnel
2. distillation
3. filtration
4. sublimation