What is 70 liters in kgs?

Answer 1

This question cannot be answered sensibly. A litre is a measure of volume, with dimensions [L3]. A kilogram is a measure of mass, with dimensions [M]. The two measure different things and basic dimensional analysis teaches that you cannot convert between measures with different dimensions such as these without additional information.
As a simple mental exercise consider a litre of air and a litre of water. They will have very different masses.

Answer 2

Different fluids weigh more so it depends on what it is.

Answer 3

70 litres converts to 18.492 US gallons or 15.3978 Imperial gallons.

Answer 4

318.15 litres

Answer 5

264.97 liters