Blog

Green light can have a wavelength of 543 nm. The energy of a photon of this light is

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.