Edexcel AS Chemistry worksheet for calculations on no. atoms, molecules, ions, etcWatch
2) The mass of one atom of 19F is 3.1546 x 10-23 g. Use this and the Avogadro constant (6.0225 x 1023) to find the mass of one mole of 19F atoms.
3) The mass of one mole of 127I atoms is 126.9045 g. Given that the Avogadro constant equals 6.0225 x 1023 and the mass of one electron equals 9.1091 x 10-28 g, calculate the mass of one mole of 127I- ions.
4) a) Calculate the Avogadro constant given that the mass of one mole of 12C atoms is 12.000 g while the mass of one 12C atom is 1.9925 x 10-23 g.
b) The relative atomic mass of carbon is 12.011 and not 12.000. Explain this difference.
5) Calculate the expected mass of one mole of a particles (4He2+ ions) given that the mass of one proton is 1.6725 x 10-24 g, the mass of one neutron is 1.6748 x 10-24 g and the Avogadro constant is 6.0225 x 1023.
6) a) The mass of one mole of 27Al atoms is 26.9185 g. Given that the Avogadro constant equals 6.0225 x 1023 and the mass of one electron equals 9.1091 x 10-28 g, calculate the mass of one mole of 27Al3+ ions.
b) Calculate the percentage difference between the mass of 27Al atoms and 27Al3+ ions, and use this to show why the mass of electrons are negligible in normal laboratory use of aluminium and other chemicals.
Taken from www.chemsheets.co.uk