Q: A sample contains 50.0 pounds of pennies. If 1 dozen = 12, 1 pound = 16 ounces, and 1 ounce = 4 quarters, how many quarters are in the sample?

$$50.0 \times \frac{16}{1} \times \frac{4}{1} = 3200$$

Q: Calculate the weighted average atomic mass of chlorine given the following isotopic abundances: $$^{35}\mathrm{Cl} (75.77$$%, mass = 34.969 amu) and $$^{37}\mathrm{Cl} (24.23$$%, mass = 36.966 amu).

$$(0.7577 \times 34.969) + (0.2423 \times 36.966) = 35.45$$

Q: How many molecules of $$\mathrm{H_2O}$$ are present in 100 g of water? ($$M_{\mathrm{H_2O}} = 18.0 g/$$mol, $$N_A = 6.022 \times 10$$^{23}$$ molecules/mol)

$$\frac{100}{18.0} \times 6.022 \times 10$$^{23}$$ = 3.3 \times 10$$^{24}$$

Q: What is the energy of a photon with a wavelength of $$500 \ \mathrm{nm}$$? ($$h = 6.63 \times 10$$^{-34}$$ \ \mathrm{J \cdot s}$$, $$c = 3.00 \times 10^8$ \ \mathrm{m/s})$$

$$E = \frac{hc}{\lambda} = \frac{6.63 \times 10$$^{-34}$$ \times 3.00 \times 10^8$}{500 \times 10$$^{-9}$$} = 3.98 \times 10$$^{-19}$$ \ \mathrm{J}$$

Question 1

Which experiment provided the first direct evidence for the existence of the electron and allowed for the calculation of its charge-to-mass ratio?

Accepted Answer

J.J. Thomson's cathode ray tube experiment

Question 2

According to Dalton's atomic theory, which statement is INCORRECT?

Accepted Answer

Atoms are created and destroyed in chemical reactions.

Question 3

A sample contains 50.0 pounds of pennies. If 1 dozen = 12, 1 pound = 16 ounces, and 1 ounce = 4 quarters, how many quarters are in the sample?

Accepted Answer

$$50.0 	imes \frac{16}{1} 	imes \frac{4}{1} = 3200$$

Question 4

Which law states that a chemical compound always contains exactly the same proportion of elements by mass?

Accepted Answer

Law of Definite Proportions

Question 5

If two elements combine to form more than one compound, the masses of one element that combine with a fixed mass of the other are in ratios of small whole numbers. This is known as:

Accepted Answer

Law of Multiple Proportions

Question 6

Which of the following best describes the result of Rutherford's gold foil experiment?

Accepted Answer

Most alpha particles passed through, but some were deflected at large angles, indicating a small, dense nucleus.

Question 7

Which subatomic particle was discovered by James Chadwick in 1932?

Accepted Answer

Neutron

Question 8

Calculate the weighted average atomic mass of chlorine given the following isotopic abundances: $$^{35}\mathrm{Cl} (75.77$$%, mass = 34.969 amu) and $$^{37}\mathrm{Cl} (24.23$$%, mass = 36.966 amu).

Accepted Answer

$$(0.7577 	imes 34.969) + (0.2423 	imes 36.966) = 35.45$$

Question 9

How many molecules of $$\mathrm{H_2O}$$ are present in 100 g of water? ($$M_{\mathrm{H_2O}} = 18.0 g/$$mol, $$N_A = 6.022 	imes 10$$^{23}$$ molecules/mol)

Accepted Answer

$$\frac{100}{18.0} 	imes 6.022 	imes 10$$^{23}$$ = 3.3 	imes 10$$^{24}$$

Question 10

Which of the following best explains why atomic emission spectra are discrete lines rather than continuous?

Accepted Answer

Electrons in atoms can only occupy certain allowed energy levels.

Question 11

What is the energy of a photon with a wavelength of $$500 \ \mathrm{nm}$$? ($$h = 6.63 	imes 10$$^{-34}$$ \ \mathrm{J \cdot s}$$, $$c = 3.00 	imes 10^8$ \ \mathrm{m/s})$$

Accepted Answer

$$E = \frac{hc}{\lambda} = \frac{6.63 	imes 10$$^{-34}$$ 	imes 3.00 	imes 10^8$}{500 	imes 10$$^{-9}$$} = 3.98 	imes 10$$^{-19}$$ \ \mathrm{J}$$

Question 12

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

Angular momentum quantum number ($$l)$$

Question 13

Which electron configuration represents the ground state of nitrogen (N, $$Z=7$$)?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^3$$

Question 14

Which of the following elements has the highest first ionization energy?

Accepted Answer

Fluorine (F)

Question 15

Which of the following statements about ionic and covalent bonds is correct?

Accepted Answer

Ionic bonds involve the transfer of electrons, while covalent bonds involve the sharing of electrons.

Question 16

What is the formal charge on the central carbon atom in carbon monoxide (CO)?

Accepted Answer

+1

Question 17

Which of the following molecules has a trigonal planar electron group geometry?

Accepted Answer

$$\mathrm{BH_3$}$$

Question 18

Which of the following best describes the resonance structure of ozone ($$\mathrm{O_3$}$$)?

Accepted Answer

The actual structure is a hybrid of two resonance forms, with bond order between a single and double bond.

Question 19

Which of the following statements about VSEPR theory is correct?

Accepted Answer

Electron groups around a central atom arrange themselves as far apart as possible to minimize repulsion.

General Chemistry I: Foundational Concepts, Atomic Structure, and Molecular Geometry

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드