Answer:
57.5%
Explanation:
The mass percent of copper in malachite (Cu2(OH)2CO3) can be determined as follow:
Molar Mass of malachite (Cu2(OH)2CO3) = (2x63.5) + 2(16 +1) + 12 + (16x3) = 127 + 2(17) + 12 + 48 = 127 + 34 + 12 + 48 = 221g/mol
Mass of Cu in Cu2(OH)2CO3 = 2 x 63.5 = 127g
The percentage by mass of Cu in Cu2(OH)2CO3 is given by:
Mass of Cu/Molar Mass of Cu2(OH)2CO3 x 100
=> 127/221 x 100
=> 57.5%
Therefore, 57.5% by mass of Cu is contained in malachite Cu2(OH)2CO3