Ablock of lead with dimensions 2.0 dm x 8.0 cm x 35 mm, has a mass of 6.356 kg. calculate the density of lead in g/cm

First, let us calculate for the volume of the block of lead using the formula:

V = l * w * h

But we have to convert all units in terms of cm:

l = 2.0 dm = 20 cm

w = 8 cm

h = 3.5 cm

Therefore the volume is:

V = (20 cm) * (8 cm) * (3.5 cm)
V = 560 cm^3

Next we convert the mass in terms of g:

m = 6.356 kg = 6356 g

Density is mass over volume, so:

density = 6356 g / 560 cm^3

density = 11.35 g / cm^3     (ANSWER)

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂