You are given the density of seawater which is 1.025 grams per milliliters and its volume at 1000 liters. You are required to find the mass of the seawater in grams and kilograms. You need to know that density is equal to mass over volume. Let us denote D as our density, V our volume and M as our mass. So,
D = M/V
M = D*V
M = (1.025 g/mL)(1000 L)(1000mL/1L)
M = 1,025,000 g
To change into kilograms, simply divide it by 1000
M = (1,025,000 g)(1kg/1000g) = 1,025kg