Q: A sample of aluminum foil has a mass of 1.07 kg. What is its mass in pounds (lb)? (1 lb = 453 g)

$$1.07 \times 1000 \div 453 = 2.36 lb$$

Q: The density of lithium is $$5.34 \times 10$$^{-2}$$ g/cm^3$. Convert this density to kg/m^3$.

$$5.34 \times 10$$^{-2}$$ \times 1000 = 53.4 kg/m$^3 ($$since $$1 g/cm$^3 = 1000 kg/m$^3)$$

Q: Express the speed of light ($$1.86 \times 10^5$ mi/s) in kilometers per hour. (1$ mi = 1.609$ km)

$$1.86 \times 10^5$ \times 1.609 \times 3600 = 1.08 \times 10^9$ km/h

Q: A cylindrical glass tube 12.7 cm in length is filled with mercury. The mass of mercury needed to fill the tube is 105.5 g. If the density of mercury is 13.6 g/mL, what is the inner radius of the tube? (Volume of cylinder $$= \pi r^2$ h)$$

$$r = \sqrt{\frac{105.5}{13.6 \times \pi \times 12.7}} = 1.44 cm$$

Question 1

Which of the following best describes a scientific law?

Accepted Answer

A statement that summarizes a large number of observations but provides no explanation.

Question 2

Which of the following is an example of a heterogeneous mixture?

Accepted Answer

Milk

Question 3

A sample of aluminum foil has a mass of 1.07 kg. What is its mass in pounds (lb)? (1 lb = 453 g)

Accepted Answer

$$1.07 	imes 1000 \div 453 = 2.36 lb$$

Question 4

Which of the following statements about significant figures is correct?

Accepted Answer

Zeros to the left of the first nonzero digit are not significant.

Question 5

The density of lithium is $$5.34 	imes 10$$^{-2}$$ g/cm^3$. Convert this density to kg/m^3$.

Accepted Answer

$$5.34 	imes 10$$^{-2}$$ 	imes 1000 = 53.4 kg/m$^3 ($$since $$1 g/cm$^3 = 1000 kg/m$^3)$$

Question 6

Which of the following is a chemical property?

Accepted Answer

Burning hydrogen gas in oxygen to form water

Question 7

A piece of metal has a mass of 134.412 g. It is placed in a graduated cylinder containing 12.35 mL of water. The final volume is 19.40 mL. What is the density of the metal in g/mL?

Accepted Answer

$$\frac{134.412}{19.40 - 12.35} = \frac{134.412}{7.05} = 19.07 g/mL$$

Question 8

Which of the following is NOT a pure substance?

Accepted Answer

Air

Question 9

Express the speed of light ($$1.86 	imes 10^5$ mi/s) in kilometers per hour. (1$ mi = 1.609$ km)

Accepted Answer

$$1.86 	imes 10^5$ 	imes 1.609 	imes 3600 = 1.08 	imes 10^9$ km/h

Question 10

Which of the following is the correct order of operations for evaluating $$(3 + 2)2^3$ - 25$$?

Accepted Answer

Parentheses, exponents, multiplication, subtraction

Question 11

A temperature reading on a Celsius thermometer equals that on a Fahrenheit thermometer at which temperature?

Accepted Answer

$$-40^\circC$$

Question 12

Which of the following is an example of an extensive property?

Accepted Answer

Mass

Question 13

When adding $$90.432$$ and $$1.1$$, how many digits should the answer have after the decimal point?

Accepted Answer

One digit

Question 14

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

Accepted Answer

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

Question 15

Which of the following is the correct formula for density?

Accepted Answer

$$d = \frac{m}{v}$$

Question 16

A cylindrical glass tube 12.7 cm in length is filled with mercury. The mass of mercury needed to fill the tube is 105.5 g. If the density of mercury is 13.6 g/mL, what is the inner radius of the tube? (Volume of cylinder $$= \pi r^2$ h)$$

Accepted Answer

$$r = \sqrt{\frac{105.5}{13.6 	imes \pi 	imes 12.7}} = 1.44 cm$$

Question 17

Which of the following is a homogeneous mixture?

Accepted Answer

Dissolved sugar in water

Question 18

Which of the following is the correct quadratic formula for solving $$ax^2 + bx + c = 0$?

Accepted Answer

$$x = \frac{-b \pm \sqrt{b^2$ - 4ac}}{2a}$$

Question 19

Which of the following is NOT a step in the scientific method?

Accepted Answer

Ignoring experimental results

General Chemistry: Science, Measurement, and Classification of Matter

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