Q: How many molecules of $$\mathrm{N_2O_4}$$ are in $$76.3\ \mathrm{g}$$ $$\mathrm{N_2O_4}$$? (Molar mass = $$92.02\ \mathrm{g/mol})$$

$$4.99 \times 10$$^{23}$$ molecules

Question 1

When filling degenerate orbitals, electrons fill them singly first, with parallel spins. What is this way of filling orbitals called?

Accepted Answer

Hund's rule

Question 2

Which of the following is the correct ground state electron configuration for arsenic (As)?

Accepted Answer

[Ar]$$4s^2$$ $$3d^{10}$$ $$4p^3$$

Question 3

How many valence electrons do the alkaline earth metals possess?

Accepted Answer

2

Question 4

Which of the following pairs of elements are the most chemically similar?

Accepted Answer

chlorine and fluorine

Question 5

Which of the following statements is TRUE?

Accepted Answer

Nonmetals are located on the right side of the periodic table.

Question 6

Arrange these elements in order of increasing atomic radius: Cs, Sb, S, Pb, Se.

Accepted Answer

S \u003c Se \u003c Sb \u003c Pb \u003c Cs

Question 7

Place the following in order of increasing first ionization energy (IE1): N, F, As.

Accepted Answer

As \u003c N \u003c F

Question 8

Which is the larger species in each pair: N or $$N^{3-}$$; Cr or $$Cr^{3+}$$?

Accepted Answer

$$N^{3-}$$; Cr

Question 9

An ionic bond is best described as:

Accepted Answer

the transfer of electrons from one atom to another, resulting in a strong attractive force.

Question 10

Give a possible molecular formula for the empirical formula C_2H_5N.

Accepted Answer

C_4H_{10}$$N_2$$

Question 11

Calculate the molar mass of $$\mathrm{Ca_3$(PO_4$)_2}.$$

Accepted Answer

$$279.21\ \mathrm{g/mol}$$

Question 12

Determine the molecular formula of a compound that has a molar mass of $$92.0\ \mathrm{g/mol}$$ and an empirical formula of $$\mathrm{NO_2$}.$$

Accepted Answer

$$\mathrm{N_2O_4}$$

Question 13

Which species has both covalent and ionic bonds?

Accepted Answer

KCN

Question 14

How many molecules of $$\mathrm{N_2O_4}$$ are in $$76.3\ \mathrm{g}$$ $$\mathrm{N_2O_4}$$? (Molar mass = $$92.02\ \mathrm{g/mol})$$

Accepted Answer

$$4.99 	imes 10$$^{23}$$ molecules

Question 15

Identify the weakest bond among the following:

Accepted Answer

single covalent bond

Question 16

Rank the following bonds in order of increasing polarity: C–H, C–C, C–N, C–O.

Accepted Answer

C–C \u003c C–H \u003c C–N \u003c C–O

Question 17

Give the number of valence electrons for methanol, $$\mathrm{CH_3OH}.$$

Accepted Answer

14

Question 18

A central atom in a three-atom molecule forms two single bonds and possesses two lone pairs of electrons. What is the molecular geometry of the molecule?

Accepted Answer

bent

Question 19

Determine the electron domain geometry (eg) and molecular geometry (mg) of $$\mathrm{BF_3$}.$$

Accepted Answer

eg = trigonal planar, mg = trigonal planar

Question 20

Which of the following molecular geometries are polar for a molecule of the form AB$$_n ($$where n = 2, 3, 4, 5, or 6)?

Accepted Answer

bent

Step-by-Step Guidance for General Chemistry I Practice Exam 2

Guida di studio - Domande di pratica

Study guide - Flashcard