Could someone please answer this chemistry question?

2017-04-15 12:25 am
CaCO3(s) + 2HNO3(aq) → Ca(NO3)2 (aq) + CO2(g) + H2O(ℓ)
Mass of 1 mol of CaCO3=100g Mass of 1 mol of Ca(NO3)2 = 164 g

2·00 g of calcium carbonate (CaCO3) was reacted with 200 cm3
of 0·1 mol l nitric acid

Take the volume of 1 mole of carbon dioxide to be 24 litres.

In the reaction
A CaCO3 is the limiting reactant

B an excess of 0·1 mol of nitric acid remains at the end of the reaction

C 1·64 g of calcium nitrate is produced by the reaction

D 480 cm3 of carbon dioxide is produced by the reaction

回答 (1)

2017-04-15 12:40 am
✔ 最佳答案
CaCO₃(s) + 2HNO₃(aq) → Ca(NO₃)₂(aq) + CO₂(g) + H₂O(ℓ)

Initial number of moles of CaCO₃ = (2.00 g) / (100 g/mol) = 0.0200 mol
Initial number of moles of HNO₃ = (0.1 mol/L) × (200/1000 L) = 0.0200 mol

According to the above equation, mole ratio CaCO₃ : HNO₃ = 1 : 2
If HNO₃ completely reacts, amount of CaCO₃ needed = (0.0200 mol) × (1/2) = 0.0100 mol < 0.0200 mol
Hence, CaCO₃ is in excess, and HNO₃ is the limiting reactant.
(A and B are false.)

According to the equation, mole ratio HNO₃ : Ca(NO₃)₂ = 2 : 1
Number of moles of HNO₃ reacted = 0.0200 mol
Number of moles of Ca(NO₃)₂ produced = (0.0200 mol) × (1/2) = 0.0100 mol
Mass of Ca(NO₃)₂ produced = (0.0100 mol) × (164 g/mol) = 1.64 g
(C is true.)

According to the equation, mole ratio HNO₃ : CO₂ = 2 : 1
Number of moles of HNO₃ reacted = 0.0200 mol
Number of moles of CO₂ produced = (0.0200 mol) × (1/2) = 0.0100 mol
Mass of Ca(NO₃)₂ produced = (0.0100 mol) × (24000 cm³/mol) = 240 cm³
(D is false.)

The answer: C. 1.64 g of calcium nitrate is produced by the reaction.


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