PEG with MW above 1000 is typically a solid with a wax-like consistency.

PEG with MW above 1000 is typically a solid with a wax-like consistency.

• A. Liquid
• B. Solid (waxlike)
• C. Gas
• D. Plasma

Answer: (B)

Molecular weight governs the physical state of polyethylene glycol (PEG). As PEG chains get longer (higher MW), they entangle more and have higher melting points, so their viscosity increases and they become less fluid at room temperature. When the MW climbs above about 1000, PEG tends to exist as a semi-crystalline solid with a wax-like texture at room temperature. This wax-like solid can soften when warmed but remains solid or semi-solid at typical ambient conditions, and it is not volatile. That’s why a PEG with MW above 1000 is described as a solid with a wax-like consistency. The other states—liquid, gas, or plasma—don’t fit because those require much lower MW (for liquids) or extreme energy conditions (for gas or plasma), which aren’t characteristic of high-MW PEGs.

Molecular weight governs the physical state of polyethylene glycol (PEG). As PEG chains get longer (higher MW), they entangle more and have higher melting points, so their viscosity increases and they become less fluid at room temperature. When the MW climbs above about 1000, PEG tends to exist as a semi-crystalline solid with a wax-like texture at room temperature. This wax-like solid can soften when warmed but remains solid or semi-solid at typical ambient conditions, and it is not volatile. That’s why a PEG with MW above 1000 is described as a solid with a wax-like consistency. The other states—liquid, gas, or plasma—don’t fit because those require much lower MW (for liquids) or extreme energy conditions (for gas or plasma), which aren’t characteristic of high-MW PEGs.