Salinity is directly positively related to seawater density.On an average, seawater density increases with increasing salinity and vice versa.E.g. Density of pure water is 1.00 g/cm3 and density of water with 35% salinity is 1.028 g/cm3.
The time gap between spring and neap is approximately 7 days. The neap tides refers to a period of moderate tides when the sun and moon are at right angles to each other. The spring tides are high tides.