Question

a densidade. da glicerina. é. 1,26 g/cm3 . quanto pesam 4l de glicerina

Answer 1

D = M/V
1cm³ = 1mL
4L = 4000mL      

1,26 =     x
   1   =  4000
x= 1,26*4000
x=5040g 

Answer 2

$d=1,26 \frac{g}{cm^{3}} \\ d=1,26.10^{3} \frac{kg}{m^{3}}\\ \\ v=4L \\ v=4 dm^{3} \\ v=4.10^{-3} m^{3}\\ \\ d= \frac{m}{v} \\ m=d.v \\ m=1,26.10^{3}.4.10^{-3} \\ m=1,26.4 \\ \boxed {m=5,04 Kg}$