Solve this:

Qb) i) Calculate the mass of residue obtained by heating 2.7 g. Ag₂CO₁ ?      [ Ag = l08  C= 12  O = 16]

       ii) How many moles of water are in 720 g of it ?

      iii) Calculate the number of atoms in 8 g of helium gas at STP.

      iv) KCIO₃ on heating decomposes to give KCl and oxygen. What is the volume of O₂ at stp liberated by 0.1 mole of KClO₃.

 

To solve this problem, we can first convert the given mass of $\text{He}$ to moles, using its molar mass ($4.00\frac{\text{g}}{\text{mol}}$, as seen from a periodic table):

$10.0\text{g He}\left(\frac{1l\text{mol}\text{He}}{4.00\text{g He}}\right)=2.50$ $\text{mol He}$

At standard temperature and pressure conditions ($1$ bar and $0^{\text{o}}\text{C}$), one mole of an ideal gas has a volume of $22.41$ $\text{L}$.

Therefore, using dimensional analysis again,

$2.50\text{mol He}\left(\frac{22.41l\text{L}}{1\text{mol He}}\right)=56.0$ $\text{L}$

Thus, $10.0$ grams of helium occupies a volume of roughly $56.0$ $\text{liters}$.
this is for 10 you can substitute 10 with 8 and do the calculation
thank you plz thumbs up