Hydrogen peroxide decomposes to yield water and oxygen gas
That is; H2O2 (l) = H2O (l) + O2(g)
The standard heat of formation; H2O2 (l) = -187.6 kJ/mol; H2O(l) = -285.8 kJ/mol
1 mole of hydrogen peroxide contains 34 g
Thus, 5.4 g contains 5.4/34 = 0.1588 moles
The moles of water produced will also be equivalent to 0.1588 moles
Heat = heat of formation of product - reactant
Therefore; Heat = (0.1588 moles × -285,8 )- (0.1588× -187.6)
= -15.594 kJ
Answer:
A. H₃O⁺ + CN⁻ → H₂O + HCN
B. OH⁻ + NH₄⁺ → NH₃ + H₂O
C. CN⁻ + NH₄⁺ → HCN + NH₃
D. HSO₄⁻ + CH₃COO⁻ → SO₄²⁻ + CH₃COOH
E. ClO⁻ + NH₃ → NO REACTION
Explanation:
Part A.
Sodium cyanide consist of Na⁺ and CN⁻ ions. CN⁻ is a conjugate base and accept H⁺ ion from nitric acid to form HCN (hydrogen cyanide).
Part B.
Ammonium chloride consist of NH₄⁺ and Cl⁻ ions. Sodium hydroxide is a strong base dissociate completely in solution convert into ammonium hydroxide and sodium chloride.
Part C.
Sodium cyanide consist of counter ion Na⁺ . CN⁻ combined with ammonium bromide to form ammonium cyanide and sodium bromide.
Part D.
Potassium hydrohen sulphate consist of potassium counter and hydrogen sulphate ion. Hydrogen sulphate combined with acetate ion to form acetic acid and sulphate ion.
Part E.
There have no reaction because hypochlorite and ammonia both are bases.
Democritus because of Greek atomism. In the 5th century BCE, Leucippus and his pupil Democritus proposed that all matter was composed of small indivisible particles called atoms.
Answer:
Ở các đơn vị hành chính tại Việt 4 điểm Nam đều tổ chức cấp chính quyền địa phương gồm có Hội đồng nhân dân và ủy ban nhân dân. Nhận định trên đúng hay sai? Tại sao?
