Answer:
see explanation below
Explanation:
First to all, this is a redox reaction, and the reaction taking place is the following:
2KMnO4 + 3H2SO4 + 5H2O2 -----> 2MnSO4 + K2SO4 + 8H2O + 5O2
According to this reaction, we can see that the mole ratio between the peroxide and the permangante is 5:2. Therefore, if the titration required 21.3 mL to reach the equivalence point, then, the moles would be:
MhVh = MpVp
h would be the hydrogen peroxide, and p the permanganate.
But like it was stated before, the mole ratio is 5:2 so:
5MhVh = 2MpVp
Replacing moles:
5nh = 2MpVp
Now, we just have to replace the given data:
nh = 2MpVp/5
nh = 2 * 1.68 * 0.0213 / 5
nh = 0.0143 moles
Now to get the mass, we just need the molecular mass of the peroxide:
MM = 2*1 + 2*16 = 34 g/mol
Finally the mass:
m = 0.0143 * 34
m = 0.4862 g
Answer:
protons and neutrons
Explanation:
The nucleus of the atom contains protons and neutrons. The electrons of the atom orbit the nucleus.
Answer:
Atomic mass of E is 128.24
Explanation:
- The percentage composition by mass of an element in a compound is given by dividing the mass of the element by the total mass of the compound and expressing it as a percentage.
- In this case; the compound Bi₂E₃
Percentage composition of bismuth = 52.07%
Percentage composition of E = 47.93%
Mass Bismuth in the compound is (2×208.9804) = 417.96 g
Therefore,
To calculate the atomic mass of E
52.07% = 417.96 g
47.93% = ?
= (47.93 × 417.96 ) ÷ 52.07 %
= 384.729
E₃ = 384.729
Therefore; E = 384.729 ÷ 3
= 128.24
The atomic mass of E is 128.24
