Blog

When a hydrogen electron makes a transition from n = 3 to n = 1, which of the following statements is true? I. Energy is emitted. II. Energy is absorbed. III. The electron loses energy. IV. The electron gains energy. V. The electron cannot make this transition.

Given the heats of the following reactions:     ∆H°(kJ) I. P4(s) + 6 Cl2(g) –> 4 PCl3(g) –1225.6 II. P4(s) + 5 O2(g) –> P4O10(s) –2967.3 III. PCl3(g) + Cl2(g) –> PCl5(g) –84.2 IV. PCl3(g) + O2(g) –> Cl3PO(g) –285.7 Calculate the value of ∆H° for the reaction below:          P4O10(s) + 6 PCl5(g) –> 10 Cl3PO(g)

C3  (Write your answers on your free response paper) Give the electron configurations in the requested formats A)  As (orbital box diagram) B)  Zn (Spectroscopic Notation) C)  Po (Noble Gas Shorthand)

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..