Purity, formulations and chromatography knowledge check

Dyes in water soluble markers may be separated by means of..

• crystallization
• sublimation
• chromatography
• sedimentation

Which ink is a mixture of different pigments? 

• red
• orange
• green
• black

This chromatogram shows five commercial dyes (X, P, Q, R and S). The pigment in dye Q Is known to cause cancer. Which dye(s) is/are safe for use?

• P only
• S only
• P and S
• P and X

Tags

NGSS.MS-PS1-2

A substance is soluble if it can be dissolved.

In paper chromatography, the most soluble solute _____________________ .

• does not move from the start point

• stays closest to the start point

• travels furthest away from the start point

• can be found in the middle of the chromatogram

The R_f value  for the blue component is 

• 0.3
• 0.7
• 10
• 3

The R_f value  for the red component is 

• 0.3
• 0.7
• 10
• 7

A pure substance shows ------------------ spot on chromat gram

• 0
• 1
• 2
• 3

What is a formulation?

• A compound that has been designed to be a useful product
• A compound that needs to be separated to make it useful
• A mixture that has been designed as a useful product
• A mixture that needs to be separated to make it useful

In paper chromatography, what is the stationary phase?

• solvent
• paper
• sample

In paper chromatography, what is the mobile phase?

• solvent
• paper
• sample