Plz solve Q3 in a sheet of paper with proper steps also can we round off 12.70% to 13% in exam will the ans be same can you check while putting 13% as value as i rounded off to whole number also can we round off the mass number of copper to 64u will the be same yes or no also put this value
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Answer:
21.325 = 21
Explanation:
Gold sample = 1g
% of copper = 12.70
Therefore , Mass of copper = 0.127 g
Mass of gold = 1 - 0.127 = 0.873 g
No. of atoms in 197g of gold = 1 mole
No. of atoms in 1 g of gold = 1mole/ 197
... 0.873 g of gold = 1mole × 0.873/197
= 171.981 mol
No. of atoms in 63.5 g of Cu = 1mole
...0.127 g if Cu = 1mole × 0.127 × 63.5
= 8.0645 mole
Ratio = 171.98 mol /8.06 mol
= 21. 325
approx 21
P.S = Approximate Answer won't change
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