Leaves (and probably other things as well) that have fallen make the soil richer from decay.
Answer:
(a) oxygen
(b) 154g (to 3sf)
(c) 79.9% (to 3sf)
Explanation:
mass (g) = moles × Mr/Ar
note: eqn means chemical equation
(a)
moles of P = 84.1 ÷ 30.973 = 2.7152 moles
moles of O2 = 85÷2(16) = 2.65625 moles
Assuming all the moles of P is used up,
moles of O2 / moles of phosphorus = 5/4 (according to balanced chemical eqn)
moles of O2 required = 5/4 × 2.7152moles = 3.394 moles (more than supplied which is 2.65625moles)
therefore there is insufficient moles of O2 and the limiting reactant is oxygen.
(b)
moles of P2O5 produced
= 2/5 (according to eqn) × 2.7152
= 1.08608moles
mass of P2O5 produced
= 1.08608 × [ 2(30.973) + 5(16) ]
= 154.164g
= approx. 154g to 3 sig. fig.
(c)
% yield = actual/theoretical yield × 100%
= 123/154 × 100%
= 79.870%
= approx. 79.9% (to 3sf)
Answer:
Titration
Explanation:
Titration is a method to determine the concentration of an unknown solution by using a known concentration solution.
The known concentration solution (titrant) - NaOH 1.0 M is added through the burette to the flask containing unknown concentration solution (analyte) - HCl. For example, if the volume of NaOH used to neutralise 20 ml of HCl is 10 ml, the concentration of HCl is 0.5M. To elaborate,
Equation: NaOH + HCl → NaCl + H2O
moles of NaOH = Concentration (mol/L) x Volume (L) = 1.0 x 0.01 = 0.01 mol
moles of NaOH = moles of HCl = 0.01 mol
⟹ concentration of HCl = moles / Volume = 0.01/0.02 = 0.5M.
CaCO₃ reacts more vigorously with HCl than with CH₃COOH because HCl is a strong acid and acetic acid is a weak acid.
<h3>What is calcium carbonate?</h3>
Calcium carbonate (CaCO₃) is a salt of strong base and weak acid so that it can react with any acid.
Among hydrochloric acid (HCl) and acetic acid (CH₃COOH), HCl is a strong acid means it completely dissociates into their respective ions and acetic acid is a weak acid. So due to strong basic nature of calcium carbonate it vigorously reacts with strong HCl acid.
Hence due to strong acidity of HCl, CaCO₃ vigorously react with HCl.
To know more about acidity, visit the below link:
brainly.com/question/19584961
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