Question

The number of oxygen atoms in 24.9 g of CuSO4.5H20 is (molar mass of Cu = 63 g mol-1)
(A) 2.41 x 1024 (B) 3.01 X 1024
(C) 5.42 x 1023 (D) 5.42 x 1024​

Answer 1

Answer:

answer is 2.41×1024

Explanation:

the answer is 2.41 x 1024

Answer 2

Given: 24.9 g of a compound CuSO4. 5H2O is given

To find: The number of oxygen atoms in this compound

Explanation: Molar mass of this compound=

1* molar mass of Cu+ 1* molar mass of sulphur+10* molar mass of hydrogen+ 9* molar mass of oxygen

= 1* 63+ 1* 32+ 10*1+ 9*16

= 63+32+10+144

=249 grams

Mass given of the compound= 24.9 gram

Moles= given mass/ molar mass

= 24.9/249

= 0.1 moles

Therefore, number of moles of oxygen atoms

= 0.1 * 9

= 0.9 moles

Number of oxygen atoms

= 0.9 * Avogadro number

= 0.9 * 6.02* 10^23

= 5.42 * 10^23 atoms

Therefore, the total number of oxygen atoms in this compound is 5.42* 10^23.