What mass of oxygen will contain 2 moles of ${\mathrm{O}}_2$ molecules? Molar mass of ${\mathrm{O}}_2$ = 32g/mol.

Calculate the number of molecules in 1.195g of chloroform$\left({\mathrm{CHCl}}_3\right)$.

Atomic masses. $\mathrm{H}=1\mathrm{u}, \mathrm{C}=12\mathrm{u}, \mathrm{Cl}=35.5\mathrm{u}$

Write the molecular formula of aluminium oxide ${\mathrm{Al}}_{\mathrm{x}}{\mathrm{O}}_{\mathrm{y}}$.

The value of x and y in the formula can be-

A. x = 1, y = 2

B. x = 2, y = 3

C. x = 3, y = 2

"Enter your correct answer as A, B or C."