Answer:
Nitrate is a polyatomic ion with the molecular formula NO⁻₃ and a molecular mass of 62.0049 u. Organic compounds that contain the nitrate ester as a functional group are also called nitrates.
A. 6 moles
B. 9 moles
C. 3 moles
D. 20 moles
I think please check me, in case I am wrong
D= mass/volume so it's 100/68 which equals 1.47cm3
Answer : The density of the block is estimated to be,
.
Explanation :
Density of the water, 
As we know that,
Buoyant force = 
where,
g = gravitational acceleration
volume of the block = v
density of the block = 
Weight of the Block = Buoyant force exerted by water




Thus, the density of the block is estimated to be,
.