Answer:
Manganese dioxide is a catalyst.
Explanation:
The decomposition of hydrogen peroxide into water and oxygen is a slow reaction and MnO₂ is used as a catalyst to speed up the reaction.
The role of MnO₂ (catalyst):
- Chemical reactions occur faster in the presence of a catalyst because the catalyst provides an alternative reaction pathway with a lower activation energy than the non-catalyzed mechanism.
- In catalyzed mechanisms, the catalyst usually reacts to form a temporary intermediate, which then regenerates the original catalyst in a cyclic process.
- A substance which provides a mechanism with a higher activation energy does not decrease the rate because the reaction can still occur by the non-catalyzed route.
- The catalyst does not used up in the reaction.
So, the right choice is:
Manganese dioxide is a catalyst.
Answer:
The answer is
<h2>69.30 g</h2>
Explanation:
The mass of a substance when given the density and volume can be found by using the formula
<h3>mass = Density × volume</h3>
From the question
volume = 42 mL
density = 1.65 g/mL
The mass is
mass = 1.65 × 42
We have the final answer as
<h3>69.3 g</h3>
Hope this helps you
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:
Phosphorus atoms can bond with oxygen atoms to form ester groups. These can bond with carbon atoms, yielding a large number of organic phosphorus chemicals. These are found in many important biological processes
Answer:
¾ litters of water was consumed
2.24 litters = 1 mole of water
Therefore ¾÷2.24 moles was consumed
0.33 moles