A steel block has a volume of 0.08m and a density of 7840 kgm?

A steel block has a volume of 0.08m and a density of 7840 kgm3 What is the force of gravity acting on the block the weight in water? A steel block has a volume of 0.08m and a density of 7840 kgm?
i don't know how to interpret the "the weight in water" phrase in terms of the rest of the question, but......

if V=0.08m^3 and density=7840kg/m^3 then
mass = density*volume = 7840kg/m^3 * 0.08m^3 = 627.2 kg

force due to gravity:
weight = m*g
weight = 627.2kg * 9.8 m/s^2 = 6147 N

at this point i am making my best guess about what that extra phrase at the end of your question was about.......
6147N = 1382 pounds
one gallon of water is 8.3 pounds. so the weight of this steel block is equivalent to the weight of 166.5 gallons (or 630.3 liters) of water.

BTW, the steel that is closest to your 7840 kg/m^3 density is "carbon steel". steel densities range from 7715 kg/m^3 (tool steel) to 8030 kg/m^3 (stainless steel)... pure iron is 7860 kg/m^3...

cheers