How many molecules of oxygen are produced from the decomposition of 8.75 g of hydrogen peroxide in the following equation Mg + H2O2 --> MgH2 + O2
options:
8.75 x 1024
6.02 x 1023
1.55 x 1022
5.27 x 1024
1.55 x 1023
Here is a worked example of a stoichiometry problem. Just follow the steps.
http://www.jiskha.com/science/chemistry/stoichiometry.html
8.75/34.02 (molar mass of H2O2) = .257 mol H2O2
Since the mol ratio b/t H2O2 and O2 is 1:1, there is also .257 mol O2
.257 mol * 6.02 * 10^23 = 1.55 * 10^24 molecules so the 3rd option.
To determine the number of molecules of oxygen produced from the decomposition of 8.75 g of hydrogen peroxide, we need to use the concept of molar mass and Avogadro's number.
First, calculate the number of moles of hydrogen peroxide using its molar mass. The molar mass of hydrogen peroxide (H2O2) is approximately 34.02 g/mol.
8.75 g H2O2 * (1 mol H2O2 / 34.02 g H2O2) = 0.257 mol H2O2
From the balanced equation, we can see that 1 mol of H2O2 produces 1 mol of O2.
Therefore, 0.257 mol H2O2 will produce 0.257 mol O2.
Now, use Avogadro's number to convert moles to molecules. Avogadro's number is approximately 6.02 x 10^23 molecules/mol.
0.257 mol O2 * (6.02 x 10^23 molecules/mol) = 1.55 x 10^23 molecules of O2
Therefore, the correct option is 1.55 x 10^23.
To determine the number of molecules of oxygen produced from the decomposition of 8.75 g of hydrogen peroxide, we first need to calculate the number of moles of hydrogen peroxide using its molar mass and the given mass.
The molar mass of hydrogen peroxide (H2O2) can be calculated by summing the molar masses of its constituent elements, which are hydrogen (H) and oxygen (O). The molar mass of hydrogen is 1.01 g/mol, and the molar mass of oxygen is 16.00 g/mol. Since there are two hydrogen atoms and two oxygen atoms in one molecule of hydrogen peroxide, we can calculate its molar mass as follows:
(2 * 1.01 g/mol) + (2 * 16.00 g/mol) = 34.02 g/mol
Now, we divide the given mass of hydrogen peroxide (8.75 g) by its molar mass (34.02 g/mol) to obtain the number of moles:
8.75 g / 34.02 g/mol = 0.257 mol
Next, we examine the balanced chemical equation for the decomposition of hydrogen peroxide:
Mg + H2O2 --> MgH2 + O2
From the equation, we can see that one mole of hydrogen peroxide (H2O2) produces one mole of oxygen (O2) when it decomposes.
Therefore, the number of moles of oxygen produced is also 0.257 mol.
To convert the number of moles of oxygen to the number of molecules, we use Avogadro's number, which states that there are 6.02 x 10^23 entities (atoms, molecules, etc.) in one mole of any substance.
Therefore, the number of molecules of oxygen produced is:
0.257 mol * (6.02 x 10^23 molecules/mol) = 1.55 x 10^23 molecules
Thus, the correct option is "1.55 x 10^23".