The coefficient for the chemical formula 3CO2 is the 3.
2F⁻ → F₂ + 2e⁻
(mainly electrochemical oxidation)
The ore contains 55.4% calcium phosphate (related to the mineral apatite) so the amount of Ca3(PO4)2 is 55.4%x=1000g so x=1000/0.554= 1.805kg. Now for the % of P in this amount of calcium phosphate, use all the masses of the elements in Ca3PO4= Ca=40.078 x 3= 120.23 and (PO4)2= (30.974+64)2=189.95 (NB oxygen is 16 mass x 4 =64) so the total mass is 310.2 and we have 61.95 of P (Pmass x 2) so 61.95/3102.= 0.19 or 19% P. So of the 1.805 x 0.19= 0.34kg of phosphorus.
Answer:
4.504g of acetic acid
Explanation:
The acetic acid in reaction with NaOH produce acetate ion, thus:
CH₃COOH + NaOH → CH₃COO⁻ + H₂O + Na⁺
<em>That means the moles of acetate buffer comes, in the first, from the acetic acid</em>
As you need 500mL (0,500L) of a 0.150M acetate buffer, moles are:
0.500L × (0.150mol / 1L) = <em>0.075 moles of acetate</em>. That is:
0.075mol = [CH₃COO⁻] + [CH₃COOH]
Thus, grams of acetic acid you need to prepare the buffer are:
0.075 moles acetic acid × (60.05g / 1mol) = <em>4.504g of acetic acid</em>
Similarities between Mendeleev's periodic and Modern periodic table: Elements are arranged in groups and periods. Elements with similar properties are placed in the same group. Metals and non-metals are placed separately.
The major difference is that the elements in Mendeleev's periodic table were arranged by atomic mass and the modern periodic table arranges elements by atomic number. Of course as elements are constantly being discovered there were significantly fewer elements in Mendeleev's periodic table.
