Answer:
Percentage Yield = 56.9% (to 3 significant figures)
Explanation:
Firstly you need to calculate the amount of moles of Na used. Moles = Mass/Mr, so moles of Na = 1.72x10^-3/23. This gets you 7.47826087x10^-5 moles.
The mole ratio of Na:Na2O is 2:1 so the moles of Na2O will be the moles of Na divided by 2. This gets you 3.739130435x10^-5 moles.
Mass = Moles x Mr
The Mr of Na2O = 62
Mass = 3.739130435x10^-5 x 62 = 2.31826087x10^-3g
Percentage Yield = (Actual Yield / Theoretical Yield) x 100
Percentage Yield = (1.32x10^-3 / 2.31826087x10^-3) x 100
Percentage Yield = 56.93923481%
Percentage Yield = 56.9% (to 3 significant figures)
Simply put, density is how tightly “stuff” is packed into a defined space.
For example, a suitcase jam-packed with clothes and souvenirs has a high density, while the same suitcase containing two pairs of underwear has low density. Size-wise, both suitcases look the same, but their density depends on the relationship between their mass and volume.
Mass is the amount of matter in an object.
Volume is the amount of space that an object takes up in three dimensions.
Density is calculated using the following equation: Density = mass/volume or D = m/v.
If something is heavy for its size, it has a high density. If an object is light for its size it has a low density.
The relative densities of an object and the liquid it is placed in determine whether that object will sink or float.
Answer:
No. of protons = 34
Explanation:
First we need to calculate the number of electrons in one mole of the the element:
No. of electrons per mole = Total Mass of Electrons/Mass of 1 Electron
No. of electrons per mole = (18.65 x 10⁻³ g)/(9.109 x 10⁻²⁸ g)
No. of electrons per mole = 2.04 x 10²⁵ electrons/mol
Now, we calculate the no. of electrons in 1 atom:
No. of electrons per atom = No. of Electrons per mole/No. of atoms per mole
No. of electrons per atom = (2.04 x 10²⁵ electrons/mol)/(6.022 x 10²³ atoms/mol)
No. of electrons per atom = 34 electrons/atom
Since, the no. of protons in a pure element are equal to the number of electrons. Therefore,
<u>No. of protons = 34</u>
This is what I got hope it helps
Hello!
The
dissociation reaction of HNO₃ is the following:
HNO₃ → H⁺ + NO₃⁻This is a strong acid, so the concentration of HNO₃ would be the same as the concentration of H⁺. The formula for pH is the following:
![pH=-log([H_3O^{+}])=-log(0,75M)=0,12](https://tex.z-dn.net/?f=pH%3D-log%28%5BH_3O%5E%7B%2B%7D%5D%29%3D-log%280%2C75M%29%3D0%2C12)
So, the pH would be
0,12Have a nice day!
