Why do some powders dissolve and some thicken the liquid? Like why does flour thicken water but sugar dissolves in it?

Question

Why do some powders dissolve and some thicken the liquid? Like why does flour thicken water but sugar dissolves in it?

In: Chemistry

Answer 1

Any powder will thicken water (or settle to the bottom) if there’s enough of it. Put enough sugar in water and it becomes syrup. The Dead Sea has so much salt in it that you can float.

Answer 2

Flour and other thickening agentd (corn starch and arrow root are 2 others) cause liquids to thicken because of starch. When added to a hot liquid, the starch molecules absorb water and swell up causing the liquid to become thicker.