Hey there!
1 mole has 6.022 x 10²³ atoms.
Multiply that by 3.2 because we have 3.2 moles.
3.2 x 6.022 x 10²³
1.9 x 10²⁴
There are 1.9 x 10²⁴ atoms in 3.2 moles of chromium.
Hope this helps!
<u>Answer:</u> The correct answer is Option d.
<u>Explanation:</u>
According to Lewis acid-base concept:
The substance which is donating electron pair is considered as Lewis base and the substance which is accepting electron pair is considered as Lewis acid.
For the given chemical reaction:

is accepting electron pair and is getting converted to
. Thus, it is considered as Lewis acid.
present in CuO is a Lewis base because it is donating electron pair.
Thus, the correct answer is Option d.
Answer:
The atoms have the same chemical symbol.
Answer:
b) 2.0 mol
Explanation:
Given data:
Number of moles of Ca needed = ?
Number of moles of water present = 4.0 mol
Solution:
Chemical equation:
Ca + 2H₂O → Ca(OH)₂ + H₂
now we will compare the moles of Ca and H₂O .
H₂O : Ca
2 : 1
4.0 : 1/2×4.0 = 2.0 mol
Thus, 2 moles of Ca are needed.
All of these are compounds except oxygen because a compound is two or more different elements bonded together.