Answer:

Explanation:
When percentage composition is given, and asked for the empirical formula, it is simplest to assume 100 g of material. Thus,
Mass C = 40.92 g. Moles C = 40.92 g x 1 mole/12 g = 3.41 moles C
Mass H = 4.58 g. Moles H = 4.58 g x 1 mole/1.0 g = 4.58 moles H
Mass O = 54.50 g. Moles O = 54.50 g x 1 mole/16 g = 3.41 moles O
Now, we want to get the moles into whole numbers, so we begin by dividing all by the smallest, i.e. divide all values by 3.41.
Moles C = 3.41/3.41 = 1
Moles H = 4.58/3.41 = 1.34
Moles O = 3.41/3.41 = 1
Now, in order to get 1.34 to be a whole number we multiply it (and all others) by 3
Moles C = 1x3 = 3
Moles H = 1.34x3 = 4
Moles O = 1x3 = 3
Empirical Formula 
Answer:
-2
Explanation:
carbonate oxifation number is -2
The correct letter to your answer would be A
<span>The ideal mechanical advantage represents the number of times the input force is multiplied under ideal conditions, that is with no friction. Actual mechanical advantage on the other hand stands for the number of times the input force is multiplied.
Hence; IMA (ideal mechanical advantage)=Le/Lr
The Lr =0.3 +1.2 = 1.5 and Le= 0.3
= 0.3/1.5
= 1/5;
therefore the correct answer is 0.2</span>
2H2 (g) + O2 (g) -->2H2 O(g)
mole ratio of H2:O2=2:1
7.25/2=3.625