請化學神人幫解化學...解法也要...謝謝

1) Which thermodynamic function is most related to disorder and probablity?

A) entropyB) enthalpyC) internal energyD) heat capacity

2) For the expansion of an ideal gas into a vacuum at constant temperature, ΔH = 0. What can be said about ΔE and ΔS?

A) ΔE is negative and ΔS is zero. B) ΔE is positive and ΔS is negative. C) ΔE is negative and ΔS is positive.D) ΔE is zero and ΔS is positive.

3) For the of freezing liquid ethanol at a given temperature and pressure,

A) ΔH is negative and ΔS is positive.B) ΔH is positive and ΔS is negative.

C) ΔH is negative and ΔS is negative.D) ΔH is positive and ΔS is positive.

4) Which of the following is not true?

A) A spontaneous reaction is one that can proceed on its own

B) The reverse of a nonspontaneous reaction is always spontaneous.

C) A spontaneous reaction need not occur immediately.

D) A spontaneous reaction must be exothermic and must have an increase in entropy.

5) What is the sum of the coefficients when the following equation is balanced using the lowest, whole numbered coefficients?

____B 2O3(s) +____HF(l) →_____BF3(g) +_____H2O(l)

A) 15 B) 8 C) 11 D) none of these

6) Aluminum metal reacts with iron(II) sulfide to form aluminum sulfide and iron metal. What is the stoichiometric coefficient for aluminum when the chemical equation is balanced using the lowest, whole-number stoichiometric coefficients?

A) 2 B) 3 C) 1 D) 4

8) How many iron(II) ions, Fe2+ are there in 5.00 g of FeSO4?

A) 1.98 × 1022 iron (II) ions B) 1.83 × 1025 iron (II) ions

C) 5.46 × 10-26 iron (II) ions D) 4.58 × 1026 iron (II) ions

9) How many oxygen atoms are in 3.00 g of sodium dichromate, Na2Cr2O7?

A) 6.90 × 1021 oxygen atoms B) 4.83 × 1022 oxygen atoms

C) 9.85 × 1020 oxygen atoms D) 0.0801 oxygen atoms

1 Answer

Rating
  • Lv 5
    1 decade ago
    Favorite Answer

    1. A

    2. E, p = 0 而且H = E + pV 所以E也=0

    3. C, become more ordered and releases heat (latent heat)

    4. B

    5. 1+2+6+3 = 12, none; D

    6. A ;2 (2Al + 3FeS = Al2S3 + 3Fe)

    8. A 1.98E22

    FeSO4 => 5/151.9x6.02E23 = 1.98E22

    9. 同上算法

    10. B; A,C = 0.5 mol, B = 1 mol

Still have questions? Get your answers by asking now.