Answer:
25
Explanation:
Step 1: Given data
Circumference of the running track (c): 400 m
Total distance completed during the race (d): 10 km
Step 2: Convert "d" to meters
We will use the conversion factor 1 km = 10³ m.
10 km × (10³ m/1 km) = 10⁴ m
Step 3: Calculate the number of laps to be completed (n)
We will use the following expression.
n = d/c
n = 10⁴ m/400 m
n = 25
The following is the arrangement of the given molecules in decreasing order of mass: 
<u>Solution:</u>
First inorder to arrange the elements in descending order of their mass we have to calculate the molecular mass of each element. The calculation is as follows:
<u>Mass of C6H14:</u>


<em>Mass of C6H14 is 86.172</em>
<u>Mass of NO2:</u>


<em>Mass of NO2 is 46.0055</em>
<u>Mass of Fe2O3:</u>


<em>Mass of Fe2O3 is 159.6882</em>
<u>Mass of CaCO:</u>


<em>Mass of CaCO will be 68.0874</em>
So, the order will be
which is 
<span>Each mole contains Avagodro's number of atoms i.e. 6.023x10^23, so
3 moles x 6.023x10^23 atoms/mole = 18.069x10^23 atoms = 1.8x19^24 atoms </span>
Answer:
1.4 mols
4th answer
Explanation:
22. 5 g of O2 in moles = (22.5/32) mols = 0.703 mol
The stoichiometry between O2 and H2O =1: 2
Therefore H2O produced = 2 * 0.703 mols=1.406 mols
Hope this helps! If you dont understand balancing equations in general, say so in the comments, I’m happy to help