calculate :- (1) Total no. of electrons , protons and neutrons of 34 g of ammonia .
and (2) the mass of 2 g atom of nitrogen
Answers
1) 1 molecule of CH4 contains electron = 10
Therefore 1 mole (6.022 x 1023 atoms) contains electron = 6.022 x 1024
2) a) 1 g atom of 14C = 14g = 6.022 x 1023 atoms = 6.022 x 1024 x 8 neutrons
Thus 14 g or 14000 mg have 6.022 x 1024 x 8 neutrons
Therefore 7mg will have neutrons = 6.022 x 1024 x 8 /14000 x 7 = 2.4088 x 1022
b) mass of 1 neutron = 1.675 x 10-27kg
Therefore mass of 2.4088 x 1021 neutrons = 2.4088 x 1021 x 1.67x 10-27 = 4.0347 x 10-6 kg
3) a) 1 mol of NH3 = 17g NH3 = 6.022 x 1023 molecules of NH3 = (6.022x1023)(7 + 3) proton = 6.022x1024 protons
Therefore 34 mg i.e 0.034 g NH3 =6.022x1024 x 0.034/1 = 1.2044x1022protons
b) mass of 1 proton = 1.6726x10-27 kg
Therefore mass of 1.2044 x 1022 protons = (1.6726x 10-27)(1.2044x1022) kg = 2.0145x 10-5 kg
No the answer will not change with change in temperature & pressure.