Sea water vs. pure water – comparison of specific weight The specific weight of sea water is __________ that of pure water:

Introduction:
Specific weight (gamma) equals rho * g. Because sea water contains dissolved salts, its density is higher than that of pure water under the same conditions, so its specific weight is higher.

Given Data / Assumptions:

• Comparison at similar temperature and pressure.
• Sea water salinity increases density relative to fresh water.
• g (acceleration due to gravity) is effectively identical for both samples.

Concept / Approach:
Since gamma = rho * g and g cancels in the comparison, the fluid with higher density has higher specific weight. Sea water has rho slightly greater than 1000 kg/m^3 (often ~1025 kg/m^3).

Step-by-Step Solution:
1) Identify property: specific weight depends on density.2) Sea water's dissolved salts increase rho.3) Therefore gamma_sea > gamma_pure.

Verification / Alternative check:
Typical values: pure water ~ 9.81 kN/m^3; sea water ~ 10.06 kN/m^3 at standard conditions, confirming the qualitative conclusion.

Why Other Options Are Wrong:

• Same as: ignores salinity effect.
• Less than: opposite of physical reality.
• Not comparable: they are directly comparable at equal conditions.

Common Pitfalls:
Confusing specific gravity with specific weight; forgetting that temperature also affects density (but both compared at the same condition).

Final Answer:
more than