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Zorluk: ZorChemical Reactions and Compounds

In an industrial wastewater neutralization facility, aqueous calcium hydroxide [Ca(OH)2Ca(OH)_2] reacts with aqueous phosphoric acid [H3PO4H_3PO_4] to yield an insoluble calcium phosphate [Ca3(PO4)2Ca_3(PO_4)_2] precipitate and liquid water [H2OH_2O]. When the chemical equation for this reaction is completely balanced using the lowest whole-number coefficients, what is the sum of all stoichiometric coefficients, and which fundamental type of chemical reaction is demonstrated?

  1. A
    Total sum of 1111; synthesis reaction
  2. B
    Total sum of 66; single replacement reaction
  3. Total sum of 1212; double replacement reactionCevap
  4. D
    Total sum of 1212; physical dissolution change

Cevap

Total sum of 1212; double replacement reaction
The balanced chemical reaction is 3Ca(OH)2+2H3PO4→Ca3(PO4)2+6H2O3Ca(OH)_2 + 2H_3PO_4 \rightarrow Ca_3(PO_4)_2 + 6H_2O. Summing all stoichiometric coefficients yields 3+2+1+6=123 + 2 + 1 + 6 = 12. Because the cations and anions of two reacting compounds trade partners to produce two new substances (an insoluble precipitate and water), the process is classified as a double replacement reaction.

Adım Adım Çözüm

1
Write the unbalanced skeleton equation for the described chemical reaction.
Ca(OH)2+H3PO4→Ca3(PO4)2+H2OCa(OH)_2 + H_3PO_4 \rightarrow Ca_3(PO_4)_2 + H_2O
Establishing the correct chemical formulas of reactants and products is the necessary starting point for stoichiometry.
2
Balance the metal cations, polyatomic phosphate ions, and remaining hydrogen and oxygen atoms.
3Ca(OH)2+2H3PO4→1Ca3(PO4)2+6H2O3Ca(OH)_2 + 2H_3PO_4 \rightarrow 1Ca_3(PO_4)_2 + 6H_2O
Balancing calcium requires 3Ca(OH)23Ca(OH)_2, balancing phosphate requires 2H3PO42H_3PO_4, which yields 66 hydrogen atoms from hydroxide and 66 from acid, forming 6H2O6H_2O and satisfying the Law of Conservation of Mass.
3
Calculate the sum of all stoichiometric coefficients in the balanced equation.
3+2+1+6=123 + 2 + 1 + 6 = 12
Every term in the balanced equation has a coefficient, where an unwritten coefficient represents exactly 11.
4
Classify the reaction mechanism based on atomic and ionic reorganization.
Double replacement (acid-base neutralization and precipitation)
The calcium cations and hydrogen ions exchange their respective polyatomic anion partners (OH−OH^- and PO43−PO_4^{3-}), which defines a double replacement reaction.

Anahtar Kavram

Balancing chemical equations and classifying chemical reaction types
Tahmini Süre:1m 30s
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Konular

Chemical Reactions and Compounds

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