Determine the following.

(a) the number of Ar atoms in a 5.49 mg sample of argon

Enter a number with the correct number of significant figures.

1 atoms
(b) the molar mass, M, of an element if the mass of a 3.50 10²² atom sample of the element is 3.87 g

Enter a number with the correct number of significant figures.

2 g/mol
(c) the mass of a sample of aluminum that contains the same number of atoms as 35.55 g of zinc

Enter a number with the correct number of significant figures.

3 g

Give the molecular formulas for the molecules whose ball-and-stick models are given here. (Type your answer using the format Ca(ClO)2 for Ca(ClO)₂.)

(a)

Answer is case sensitive.

1
(b)

Answer is case sensitive.

2
(c)

Answer is case sensitive.

3
(d)

Answer is case sensitive.

4
(e)

Answer is case sensitive.

5

The u_rms of H₂ molecules at 273 K is 1.84 10³ m/s. At what temperature is u_rms for H₂ five times this value?

Enter a number.

1 K

For the reaction given below, if the H₂O were obtained as a gas rather than a liquid, answer the following.

C₂H₄(g) + 3 O₂(g) 2 CO₂(g) + 2 H₂O(l)        H° = -1410.9 kJ

(a) Would the heat of reaction be greater (more negative) or smaller (less negative) than that indicated in the equation?

1

greater smaller     same

(b) Explain your answer.
2
(c) Now calculate the value of H in this case.

Enter a number with the correct number of significant figures.

3 kJ

Concerning the concept of subshells and orbitals, determine the following.

(a) How many subshells are found in the n = 3 level?

Enter an exact number.

1
(b) What are the names of the subshells in the n = 3 level? (Select all that apply.)

2

3g 3f 3s 3d 2s 3p 2d

(c) How many orbitals have the values n = 4 and = 0?

Enter an exact number.

3
(d) How many orbitals have the values n = 5, = 3, and m = -1?

Enter an exact number.

4
(e) What is the total number of orbitals in the n = 3 level?

Enter an exact number.

5