Which one of the following compounds is insoluble in water?

a. BaSO4

b. KNO3

c. Na2SO4

d. Li2CO3

The correct option is;

a. BaSO4.

Explanation:

a. BaSO₄ Insoluble

From the solubility table, we have all sulfates SO₄ are soluble except those of Sr²⁺, Ag⁺, Ca²⁺ ,Pb²⁺ Ba²⁺,  Hg²⁺

b. KNO₃ Soluble

All nitrates are soluble, no exceptions

c. Na₂SO₄ Soluble

Sodium sulfate is among the soluble sulfates.

d. Li₂CO₃ Soluble

All carbonates are insoluble except those of NH₄⁺ and group IA.

a graduated cylinder.

explanation:

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.