Answer:
The mass of formed sodium sulphate solution is 14.2 g.
Explanation:
From the given,
Mass of copper sulphate = 15.9 g
Mass of sodium sulphide = 7.8 g
Total mass of reactant = Mass of copper sulphate + Mass of sodium sulphide
= 15.9 + 7.8g = 23.7g
Mass of copper sulphide formed = 9.5 g
Mass of sodium sulphate = Total mass - Mass of copper sulphide
= 23.7 g - 9.5 g = 14.2 g
Therefore, The mass of formed sodium sulphate solution is 14.2 g.
Answer:
400.197mmHg
Explanation:
P1V1 / T1 = P2V2 / T2
Where P1=524 mm Hg V1 =275 ml T1 = 35°C +273 = 308k
V2= 325-ml T2= 5°C+273 = 278k , P2= ?
Substituting the values into the formula.
524 mm Hg ×275 ml /308k = P2×325-ml/278k
Cross multiply
524 mm Hg ×275 ml×278k=308k×P2×325-ml
40059800= 100100×P2
P2 = 40059800/100100
P2= 400.197mmHg
Hence, the second pressure will be 400.197mmHg
Answer: NaCl (s) → NaCl (aq)
Explanation:
Entropy is often associated with the disorder or randomness of a system. Therefore, in each reaction, it is necessary to evaluate if the disorder increases or decreases to understand what happens to the entropy:
1) KCl (aq) + AgNO₃ (aq) → KNO₃ (aq) + AgCl (s) - In this reaction, we have only aqueous reactants in the beginning and in the product we have a precipitate. The solid state is more organised than the liquid, consequently, the entropy decreases.
2) NaCl (s) → NaCl (aq) - In this case, oposite to the first one, we go from a solid state to an aqueous state. The solvation of the ions Na⁺ and Cl⁻ is random while the solid state is very organised. Therefore, in this reaction the entropy increases.
3) 2NaOH (aq) + CO₂ (g) → Na₂CO₃ (aq) + H₂O (l) - In this reaction, the reactants have higher entropy because of the gas CO₂. Therefore, the entropy decreases.
4) C₂H₅OH (g) → C₂H₅OH (l) - In this reaction, the reactant is a gas and the product a liquid. Therefore, the entropy decreases.
