Year 11 moles (1 Viewer)

[Gtsh]

I need help with these 2 mole questions from the person book.

Find the relative atomic mass of nickel if 3.370g nickel was obtained by reduction of 4.286g of the oxide (NiO). You may need to refer to the periodic table at the end of this book.

16 4.150g tungsten was burned in chlorine and 8.950g tungsten chloride (WCIJ was formed. Find the relative atomic mass of tungsten. You may need to refer to the periodic table at the end of this book.

Thanks

 

[jimmysmith560]

Would the following working help with the first question?

m(Ni) = 3.370 g

m(NiO) = 4.286 g

So m(O) = 4.286 - 3.370 = 0.916 g

n(Ni) = n(O) since n(Ni) : n(O) = 1:1

n(O) = m/M = 0.916/16 = 0.05725 mol = n(Ni)

Now M(Ni) = m/n = 3.370/0.05725 = 58.86 g/mol (this is the molar mass)

The relative atomic mass of Nickel is 58.86 (≈ 58.9) atomic mass units.

 

[Gtsh]

I get everthing except the 'n(Ni) = n(O) since n(Ni) : n(O) = 1:1'. Is it because NiO have a 1 to 1 ratio

 

[jimmysmith560]

I get everthing except the 'n(Ni) = n(O) since n(Ni) : n(O) = 1:1'. Is it because NiO have a 1 to 1 ratio

Yes I believe this is the case.

 

[Gtsh]

That makes sense. Thankyou!