Blog

CH4(g) + 4Cl2(g) –> CCl4(g) + 4HCl(g), ∆H = –434 kJBased on the above reaction, what energy change occurs when 1.2 moles of methane (CH4) reacts?

Given the equation S(s) + O2(g) –> SO2(g), ∆H = –296 kJ, which of the following statement(s) is (are) true?  I.  The reaction is exothermic.II.  When 0.500 mole sulfur is reacted, 148 kJ of energy is released.III.  When 32.0 g of sulfur are burned, 2.96 x 105 J of energy is released.

Which of the following electron configurations is different from that expected?

The ∆H value for the reaction is -90.8 kJ. How much heat is released when 66.9 g Hg is reacted with oxygen?

For the reaction:               AgI(s) + Br2(g) –> AgBr(s) + I2(s), ∆H° = –54.0 kJ               ∆Hf° for AgBr(s) = –100.4 kJ/mol               ∆Hf° for Br2(g) = +30.9 kJ/molThe value of ∆Hf° for AgI(s) is:

A 36.2 g piece of metal is heated to 81°C and dropped into a calorimeter containing 50.0 g of  water (specific heat capacity of water is 4.18 J/g°C) initially at 21.7°C. The empty calorimeter has a heat capacity of 125 J/K.  The final temperature of the water is 29.7°C. Ignoring significant figures, calculate the specific heat of the metal..

Consider the following processes:   ∆H (kJ/mol) 3B –> 2C + D –125. (1/2)A –> B   150 E + A –> D   350 Calculate ∆H for: B –> E + 2C

B1  (Show your work on your Free Response Paper for full credit) At 25°C, the following heats of reaction are known:   ∆H (kJ/mol) 2ClF + O2 –> Cl2O + F2O 167.4 2ClF3 + 2O2 –> Cl2O + 3F2O 341.4 2F2 + O2 –> 2F2O –43.4 At the same temperature, calculate ∆H for the reaction: ClF + F2 –> ClF3

Fe has __________ that is (are) unpaired in its d orbitals.

Nitric acid, HNO3, was first prepared 1200 years ago by heating naturally occurring sodium nitrate (called saltpeter) with sulfuric acid to produce sodium bisulfate and collecting the vapors of HNO3 produced.  Calculate DH°rxn for this reaction.  ∆H°f[NaNO3(s)] = -467.8 kJ/mol; ∆H°f[NaHSO4(s)] = -1125.5 kJ/mol; ∆H°f[H2SO4(l)] = -814.0 kJ/mol; ∆H°f[HNO3(g)] = -135.1 kJ/mol.NaNO3(s)  +  H2SO4(l)  =>   NaHSO4(s) + HNO3(g)