A) 5Ca(OH)₂ + 3H₃PO₄ → Ca₅(PO₄)₃(OH) + 9H₂O
B) m=158 g; w=0.830; m{Ca(OH)₂}=123 g
n(H₃PO₄) = m(H₃PO₄)/M(H₃PO₄) = mw/M(H₃PO₄)
n(H₃PO₄) = 158g*0.830/(98.0g/mol) = 1.3382 mol
n{Ca(OH)₂}=m{Ca(OH)₂}/M{Ca(OH)₂}
n{Ca(OH)₂}=123g/(74.01g/mol)=1.6619 mol
Ca(OH)₂:H₃PO₄ = 5:3
1.6619:1.3382 = 5:4 the limiting reagent is a calcium hydroxide
m{Ca₅(PO₄)₃(OH)} = M{Ca₅(PO₄)₃(OH)}n{Ca(OH)₂}/5
m{Ca₅(PO₄)₃(OH)} = 502.3g/mol*1.6619/5=166.954 g*
*The statement of the problem is incorrect, surplus of a phosphoric acid reacts with a hydroxyapatite. The calculated quantity of a hydroxyapatite is not formed.
3Ca₅(PO₄)₃OH + H₃PO₄ = 5Ca₃(PO₄)₂ + 3H₂O
Answer: :)
Explanation:
In a covalent bond, the atoms bond by sharing electrons. Covalent bonds usually occur between nonmetals. For example, in water (H2O) each hydrogen (H) and oxygen (O) share a pair of electrons to make a molecule of two hydrogen atoms single bonded to a single oxygen atom
Na is the symbol for sodium.
Answer:
Water molecules pull the sodium and chloride ions apart, breaking the ionic bond that held them together. After the salt compounds are pulled apart, the sodium and chloride atoms are surrounded by water molecules, as this diagram shows. Once this happens, the salt is dissolved, resulting in a homogeneous solution.
Explanation:
<span>Earthquakes
are frightening and often dangerous to Earth. The disturbances in Earth’s crust
causes destructions and fatality. The world’s seismic energy is release in the
form of damaging earthquakes have been
concentrated along the Pacific Ocean where it meets the Western coast of North,
Central and South America. Specifically, west of the Rocky Mountains, from
California to Alaska, in Missouri and reaches across Japan, Philippines,
Indonesia, China and Australia.</span>