Q: A block of wood has a mass of 0.388 mg and a volume of 0.588 L. What is the density in $$\mathrm{g/cm}^3$$?

$$d = \frac{0.388\ \mathrm{mg} \times \frac{1\ \mathrm{g}}{1000\ \mathrm{mg}}}{0.588\ \mathrm{L} \times \frac{1000\ \mathrm{cm}^3}{1\ \mathrm{L}}} = 6.6 \times 10$$^{-7}$$\ \mathrm{g/cm}^3$$

Q: A sample of iron has a mass of $$4.360 \times 10^3$\ \mathrm{mm}^3. If $$the density of iron is $$7.86\ \mathrm{g/cm}^3$$, what is the mass in mg?

$$4.360 \times 10^3$\ \mathrm{mm}^3 \times \frac{1\ \mathrm{cm}^3}{1000\ \mathrm{mm}^3} \times 7.86\ \mathrm{g/cm}^3 \times \frac{1000\ \mathrm{mg}}{1\ \mathrm{g}} = 34,300\ \mathrm{mg}$$

Question 1

Which of the following best describes the difference between a scientific law and a scientific theory?

Accepted Answer

A law summarizes a series of related observations, while a theory gives the underlying reasons for them.

Question 2

A sample of a substance has a mass of 12.0 g and a volume of 8.0 cm$$^3. $$What is its density?

Accepted Answer

$$d = \frac{12.0\ \mathrm{g}}{8.0\ \mathrm{cm}^3} = 1.5\ \mathrm{g/cm}^3$$

Question 3

Which of the following is an example of a chemical property?

Accepted Answer

Reactivity with acids

Question 4

Convert 310.2 K to degrees Celsius and degrees Fahrenheit.

Accepted Answer

$$T_C = 310.2 - 273.15 = 37.05^\circ\mathrm{C}$$, $$T_F = 1.8 	imes 37.05 + 32 = 98.7^\circ\mathrm{F}$$

Question 5

Which separation technique would be most appropriate to separate a mixture of sand and salt water?

Accepted Answer

Filtration

Question 6

A block of wood has a mass of 0.388 mg and a volume of 0.588 L. What is the density in $$\mathrm{g/cm}^3$$?

Accepted Answer

$$d = \frac{0.388\ \mathrm{mg} 	imes \frac{1\ \mathrm{g}}{1000\ \mathrm{mg}}}{0.588\ \mathrm{L} 	imes \frac{1000\ \mathrm{cm}^3}{1\ \mathrm{L}}} = 6.6 	imes 10$$^{-7}$$\ \mathrm{g/cm}^3$$

Question 7

Which of the following is an intensive property?

Accepted Answer

Density

Question 8

A vial weighs 32.65 g when empty and 179.56 g when filled with mercury. If the density of mercury is $$13.6\ \mathrm{g/cm}^3$$, what is the volume of mercury in the vial?

Accepted Answer

$$V = \frac{179.56\ \mathrm{g} - 32.65\ \mathrm{g}}{13.6\ \mathrm{g/cm}^3} = 10.8\ \mathrm{cm}^3$$

Question 9

Which of the following is a homogeneous mixture?

Accepted Answer

Tea with sugar

Question 10

Which of the following is a physical change?

Accepted Answer

Melting of ice

Question 11

A student measures the mass of a lead block four times and gets 10.01 g, 9.99 g, 10.02 g, and 10.00 g. The true mass is 10.00 g. Which statement is correct?

Accepted Answer

The measurements are both precise and accurate.

Question 12

Which of the following is the correct conversion factor to convert from nanometers to centimeters?

Accepted Answer

$$1\ \mathrm{cm} = 10^7$\ \mathrm{nm}$$

Question 13

Which of the following best describes the energy change when water boils?

Accepted Answer

Thermal energy is absorbed, increasing the kinetic energy of the molecules.

Question 14

Which of the following is NOT a base SI unit?

Accepted Answer

Liter (L)

Question 15

A sample of iron has a mass of $$4.360 	imes 10^3$\ \mathrm{mm}^3. If $$the density of iron is $$7.86\ \mathrm{g/cm}^3$$, what is the mass in mg?

Accepted Answer

$$4.360 	imes 10^3$\ \mathrm{mm}^3 	imes \frac{1\ \mathrm{cm}^3}{1000\ \mathrm{mm}^3} 	imes 7.86\ \mathrm{g/cm}^3 	imes \frac{1000\ \mathrm{mg}}{1\ \mathrm{g}} = 34,300\ \mathrm{mg}$$

Question 16

Which of the following is a compound?

Accepted Answer

Hydrogen peroxide (H$$_2O$_2)$$

Question 17

Which of the following is the correct rule for significant figures when multiplying or dividing measured values?

Accepted Answer

The answer should have as many significant figures as the measurement with the fewest significant figures.

Question 18

Which of the following is a physical property of water?

Accepted Answer

It boils at $$100^\circ\mathrm{C} at 1 $$atm.

Question 19

Which of the following best describes the law of conservation of energy?

Accepted Answer

Energy is neither created nor destroyed in a physical or chemical change.

Chapter 1: Matter, Measurement, and Problem Solving – General Chemistry Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard