1 )Find number of gram atom, no.of gram molecule in 40g of oxygen gas (at mass O=16)

2) Find no. of He atom in sample of helium weighing 54amu (He=4)

3)Find the no. of atoms of each type in 3.42g of C_{12}H_{22}O_{11}.

4)Find no. of SO_{2 }molecules in 4.48lt at STP.

5)Find no. of electrons in 3.2g of CH_{2}.

6)Find no.of moles of carbon in 3 moles of K_{4}{Fe(CN)_{6}}

7) 2*10^{21} of x weigh 2g find molar mass.

8)Find the weight of NH_{3} which has the same no. of atoms as in 3.6g of H_{2}O.

9)Chlorophyll contains 20% Mg by weight. Find the no. of Mg atoms in 40g of chlorophyll.

10) Find weight of 50ml of SO_{2} under STP.

11)Find weight of 6 moles of H_{2}SO_{4 }and 10^{21 }molecules of CO2.

12)Find no. of nuetrons in 3.6g of H_{2}O.

13)Find no. of electrons in 40g of CO_{3} ^{2-}

14) Find weight of oxygen present in 6 moles of Na_{2}SO_{4.}10H_{2}O

15) 20ml of H_{2}O evaporate in 1 hour. Find no. of water molecules escaping in one second.

16)If a person spends one million rupees daily, find no. of years it would take him to spend avagadro no. of rupees.

17) If 3.22g of Na_{2}SO_{4.}xH_{2}O has 6.022*10^{22 }molecules of water. What is the values of x?

Given mass of oxygen = 40g

Number of gram atoms in 16g of oxygen = 1 gram atom

Number of gram atoms in 40g of oxygen = $\frac{1}{16}\times 40=2.5\mathrm{gram}\mathrm{atoms}$

Number of gram molecules in 32g of oxygen = 1 gram molecule.

Number of gram molecules in 40g of oxygen = $\frac{1}{32}\times 40=1.25\mathrm{gram}\mathrm{molecules}$

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