Answer:
Amount of Na = 2.17moles
Explanation:
Mass of Na = 50g
Molar mass of Na = 23g/mol
Amount of mole = mass/molar mass
Amount of mole = 50/23
Amount of mole = 2.17moles
Answer:
I hope this is it. I'm not really sure.
Answer:
Value of
for the given redox reaction is 
Explanation:
Redox reaction with states of species:

Reaction quotient for this redox reaction:
![Q_{p}=\frac{[Cr^{3+}]^{2}.P_{Cl_{2}}^{3}}{[H^{+}]^{14}.[Cr_{2}O_{7}^{2-}].[Cl^{-}]^{6}}](https://tex.z-dn.net/?f=Q_%7Bp%7D%3D%5Cfrac%7B%5BCr%5E%7B3%2B%7D%5D%5E%7B2%7D.P_%7BCl_%7B2%7D%7D%5E%7B3%7D%7D%7B%5BH%5E%7B%2B%7D%5D%5E%7B14%7D.%5BCr_%7B2%7DO_%7B7%7D%5E%7B2-%7D%5D.%5BCl%5E%7B-%7D%5D%5E%7B6%7D%7D)
Species inside third braket represent concentration in molarity, P represent pressure in atm and concentration of
is taken as 1 due to the fact that
is a pure liquid.
![pH=-log[H^{+}]](https://tex.z-dn.net/?f=pH%3D-log%5BH%5E%7B%2B%7D%5D)
So, ![[H^{+}]=10^{-pH}](https://tex.z-dn.net/?f=%5BH%5E%7B%2B%7D%5D%3D10%5E%7B-pH%7D)
Plug in all the given values in the equation of
:

We determine the percent by mass of water in the compound by dividing the mass of water by the total mass. The total mass of Na2SO4.10H2O is equal to 322 g. The mass of water is 180 g.
percent by mass of water = (180 / 322)*(100 %) = 55.9%
Answer:
- The standard form of a chemical element is the natural mixture of several isotopes of the same element, which is atoms with the same number of protons but different number of neutrons, while an isotope is a particular kind of atom with a definite number of neutrons.
Explanation:
A <em>chemical element</em> is a pure substance formed by atoms with the same atomic number (number of protons). This is because it is the number of protons what identifies an element.
For example: oxygen is a chemical element, so oxygen is formed by only atoms of oxygen, and the atomic number of those atoms is 8, because every oxygen atom has 8 protons.
Nevertheless, some atoms of oxygen, may have different number of neutrons. Isotopes are different kind of atoms of the same element, which only differ in the number of neutrons. So, some atoms of oxygen will have 8 neutrons, other 9 neutrons, and other 10 neutrons (those are the stable isotopes of oxygen).
That difference in neutrons, is generally accepted that, does not modifiy substantially the chemical properties of the element, but the mass number. So, the isotopes with more neutrons wil be heavier, and the isotopes with less neutrons will be lighter.
- Mass number = number of protons + number of neutrons.
In general a chemical element is formed by a mixutre of isotopes of the same element.