Answer:
Paleontologists have uncovered new fossils from Tiktaalik roseae, which, while still a fish, is considered a transitional fossil that also has traits common to the first four-footed animals. This more complete picture of Tiktaalik suggests that the creature had strong, mobile hind fins.
Explanation:
hope this helps :P
<span>Among important crop plants, nitrogen-fixing root nodules are most commonly an attribute of
B) legumes</span>
Answer: 3.01 x 10^24 atoms
Explanation:
Based on Avogadro's law:
1 mole of any substance has 6.02 x 10^23 atoms
So, 1 mole of water = 6.02 x 10^23 atoms
5 moles of water = Z atoms
To get the value of Z, cross multiply
Z x 1 mole = (6.02 x 10^23 atoms x 5 moles)
Z•mole = 30.1 x 10^23 atoms•mole
Divide both sides by 1 mole
Z•mole/1 mole = 30.1 x 10^23 atoms•mole/ 1 mole
Z = 30.1 x 10^23 atoms
[Place the value of Z in standard form]
Z = 3.01 x 10^24 atoms
Thus, there are 3.01 x 10^24 atoms in 5 mole of water
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
