Question

3. What is the number of molecules present in
0.5 mole of hydrogen?
4. What is the mass in grams of 3 moles of N?
5. Calculate the mass of 12.0 x 1014 atoms of
hydrogen.
6. Calculate the percentage composition of
(i) iron in ferric oxide, Fe2O3 (atomic mass of
Fe = 56
(ii) nitrogen in urea, H2NCONH2
7. If one mole of carbon atoms weighs 12 grams,
calculate the mass in grams of 1 atom of carbon.
8. How many grams of sodium will have the
same number of atoms as 6 grams of
magnesium? (Na = 23, Mg = 24)​

Answer 1

Answer:

Density of water(d) = 1 g/cc

According to the formula, Mass(m)=Density(d)* Volume(v)

Hence mass of 18 cc of water =1*18 g =18 g

Molar mass of water is 18 g/mol.

No. of moles of water= 1

1 mole of any substance would contain 6.023* 10^23 no. of electron, atom, ion, molecule depending on the nature of the substance, known as Avogadro’s number.

Hence, number of molecules present in 18 cc of water is 6.023* 10^23

Explanation:

Answer 2

Answer:

3.011into 10 to the power 23