Q: Convert 5.00 meters to nanometers ($$1\ \mathrm{m} = 1 \times 10^9$\ \mathrm{nm}).$$

$$5.00\ \mathrm{m} \times 1 \times 10^9$\ \mathrm{nm}/\mathrm{m} = 5.00 \times 10^9$\ \mathrm{nm}$$

Question 1

Which separation technique would be most effective for separating a mixture of sand (SiO$$_2) $$and table salt (NaCl)?

Accepted Answer

Filtration after dissolving in water

Question 2

A solution contains methanol (CH$$_3OH$$, boiling point 64.7°C) and water (boiling point 100°C). Which method would best separate these two liquids?

Accepted Answer

Distillation

Question 3

Which of the following statements about energy is TRUE?

Accepted Answer

The total energy of a system remains constant according to the law of conservation of energy.

Question 4

A nugget suspected to be gold has a mass of 22.5 g and a volume of 2.38 cm$$^3. $$What is its density?

Accepted Answer

$$d = \frac{22.5\ \mathrm{g}}{2.38\ \mathrm{cm}^3} = 9.45\ \mathrm{g/cm}^3$$

Question 5

Which of the following is the correct SI base unit for temperature?

Accepted Answer

Kelvin (K)

Question 6

Convert 5.00 meters to nanometers ($$1\ \mathrm{m} = 1 	imes 10^9$\ \mathrm{nm}).$$

Accepted Answer

$$5.00\ \mathrm{m} 	imes 1 	imes 10^9$\ \mathrm{nm}/\mathrm{m} = 5.00 	imes 10^9$\ \mathrm{nm}$$

Question 7

Which of the following numbers has 4 significant figures?

Accepted Answer

3.400

Question 8

A student measures the mass of a sample three times and gets values of 2.34 g, 2.35 g, and 2.33 g. The true mass is 2.50 g. Which statement best describes the measurements?

Accepted Answer

The measurements are precise but not accurate.

Question 9

Which of the following is an example of a physical change?

Accepted Answer

Dissolving salt in water

Question 10

How many significant figures are in the measurement 0.00540 kg?

Accepted Answer

3

Question 11

Which metric prefix represents $$10^{-6}$$?

Accepted Answer

micro-

Question 12

A sample of water has a mass of 250 g and a volume of 250 mL. What is its density?

Accepted Answer

$$d = \frac{250\ \mathrm{g}}{250\ \mathrm{mL}} = 1.00\ \mathrm{g/mL}$$

Question 13

Which of the following is the correct conversion from Celsius to Kelvin?

Accepted Answer

$$K = ^\circ C + 273.15$$

Question 14

A student calculates $$1.052 	imes 12.054 	imes 0.53. $$How many significant figures should the answer have?

Accepted Answer

2

Question 15

Which of the following is an intensive property?

Accepted Answer

Density

Question 16

Which of the following is the correct scientific notation for 0.00000057?

Accepted Answer

$$5.7 	imes 10$$^{-7}$$

Question 17

Which of the following statements about significant figures is correct?

Accepted Answer

Zeros between nonzero digits are always significant.

Question 18

A mixture of ammonium chloride (NH$$_4Cl) $$and sodium chloride (NaCl) is heated to 600°C. What will happen?

Accepted Answer

NH$$_4Cl $$will sublime, NaCl will remain as a solid.

Question 19

Which of the following is the correct conversion factor to convert millimeters to meters?

Accepted Answer

$$1\ \mathrm{mm} = 10$$^{-3}$$\ \mathrm{m}$$

General Chemistry I: Separation of Mixtures, Energy, Units, Conversion Factors, and Significant Figures

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