Q: A NASA spacecraft was lost due to a failure to convert units properly. If a calculation required the conversion of 3.60 cm to kilometers, which of the following is the correct answer?

$$3.60 \times 10$$^{-5}$$\ \mathrm{km}$$

Q: A patient was given 0.5 g of phenobarbital instead of 0.5 grains. If 1 grain = 64.8 mg, how many times more drug did the patient receive than prescribed?

$$\frac{0.5\ \mathrm{g}}{0.5 \times 64.8\ \mathrm{mg}} = 15.4$$

Question 1

A NASA spacecraft was lost due to a failure to convert units properly. If a calculation required the conversion of 3.60 cm to kilometers, which of the following is the correct answer?

Accepted Answer

$$3.60 	imes 10$$^{-5}$$\ \mathrm{km}$$

Question 2

A patient was given 0.5 g of phenobarbital instead of 0.5 grains. If 1 grain = 64.8 mg, how many times more drug did the patient receive than prescribed?

Accepted Answer

$$\frac{0.5\ \mathrm{g}}{0.5 	imes 64.8\ \mathrm{mg}} = 15.4$$

Question 3

Which of the following best describes the difference between accuracy and precision?

Accepted Answer

Accuracy is how close a measurement is to the true value; precision is how close repeated measurements are to each other.

Question 4

How many significant figures are in the measurement 0.00120 L?

Accepted Answer

3

Question 5

A student adds 2.5 kg, 1.64 kg, and 0.253 kg. What is the sum, rounded to the correct number of significant figures?

Accepted Answer

$$4.39\ \mathrm{kg}$$

Question 6

Which of the following is the correct electron configuration for a ground-state Fe atom?

Accepted Answer

$$[\mathrm{Ar}]\ 4s^2$\ 3d^6$

Question 7

Which of the following compounds contains both ionic and covalent bonds?

Accepted Answer

$$\mathrm{CaCO}_3$$

Question 8

What is the molarity of a solution containing 5.12 g of $$(NH_4$)_2SO_4 in 250.0 mL of $$solution? (Molar mass = 132.14 g/mol)

Accepted Answer

$$0.155\ \mathrm{M}$$

Question 9

Which of the following best describes a polar covalent bond?

Accepted Answer

A bond in which electrons are shared unequally between two atoms.

Question 10

Which of the following molecules is nonpolar, despite having polar bonds?

Accepted Answer

$$\mathrm{CO}_2$$

Question 11

Which of the following is the dominant intermolecular force in liquid ammonia ($$NH_3$$)?

Accepted Answer

Hydrogen bonding

Question 12

A sample contains $$3.24$$ mol of $$H_2O. $$How many molecules of water are present?

Accepted Answer

$$1.95 	imes 10$$^{24}$$

Question 13

Which of the following is the empirical formula for a compound that is 70.57% C, 5.92% H, and the rest O by mass?

Accepted Answer

$$C_4H_4O$$

Question 14

Which of the following is the correct net ionic equation for the reaction between $$AgNO_3(aq$$)$$ and $$NaCl(aq)$$?

Accepted Answer

$$Ag^+(aq) + Cl^-(aq) \rightarrow AgCl(s)$$

Question 15

Which of the following is the correct order of increasing atomic radius?

Accepted Answer

$$F \u003c Cl \u003c Br \u003c I$$

Question 16

Which of the following is the correct formula for strontium hydroxide?

Accepted Answer

$$Sr(OH)_2$$

Question 17

Which of the following statements about the Bohr model of the atom is correct?

Accepted Answer

Electrons move in fixed orbits around the nucleus with quantized energies.

Question 18

Which of the following is the correct expression for the energy of a photon?

Accepted Answer

$$E = h
u$$

Question 19

Which of the following best describes Hund's rule?

Accepted Answer

Electrons fill degenerate orbitals singly before pairing.

General Chemistry Study Notes: Essential Ideas, Atomic Theory, Measurement, and Chemical Structure

Guida di studio - Domande di pratica

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