Q: Which of the following is an example of an exact number in chemistry?

The number of atoms in 1 mole ($$6.022 \times 10$$^{23}$$).

Q: If you need to convert $$7.25$$ days to seconds, which conversion factors would you use?

$$1\ \text{day} = 24\ \text{hours},\ 1\ \text{hour} = 60\ \text{minutes},\ 1\ \text{minute} = 60\ \text{seconds}$$

Question 1

Which of the following best describes a chemical, as defined in chemistry?

Accepted Answer

A substance that always has the same composition and properties wherever it is found.

Question 2

Which of the following is an example of an exact number in chemistry?

Accepted Answer

The number of atoms in 1 mole ($$6.022 	imes 10$$^{23}$$).

Question 3

How many significant figures are in the number 0.0030?

Accepted Answer

2

Question 4

Convert 0.000000006298 to scientific notation.

Accepted Answer

$$6.298 	imes 10$$^{-9}$$

Question 5

A chemist multiplies three measurements: $$9.2 cm$$, $$6.83 cm$$, and $$0.3774 cm. $$What is the correct number of significant figures in the final answer?

Accepted Answer

2

Question 6

Which rule should be followed when rounding numbers in a multistep calculation?

Accepted Answer

Round at the very end of the calculation.

Question 7

What is the density of a substance with a mass of $$45.00 g $$and a volume of $$26.4 mL$$?

Accepted Answer

$$1.70 g/mL$$

Question 8

A glass cylinder contains four liquid layers: mercury ($$d = 13.6 g/mL$$), chloroform ($$d = 1.49 g/mL$$), water ($$d = 1.00 g/mL$$), and ether ($$d = 0.708 g/mL). If an $$aluminum bead ($$d = 2.70 g/mL) is $$dropped into the cylinder, where does it come to rest?

Accepted Answer

On the bottom of the cylinder

Question 9

What is the mass (in kg) of $$2.00 L of an $$intravenous glucose solution with a density of $$1.15 g/mL$$?

Accepted Answer

$$2.30 kg$$

Question 10

Which of the following is NOT a fundamental SI unit?

Accepted Answer

Gram

Question 11

How many millimeters are there in $$2.6785$$ kilometers?

Accepted Answer

$$2,678,500$$\ mm$

Question 12

A solid completely submerged in water displaces its own volume of water. If the water level rises from $$25.0 mL to$$ $$33.0 mL $$after a metal is added, what is the volume of the metal?

Accepted Answer

$$8.0 mL$$

Question 13

What is the density (g/cm$$^3) of$$ $$48.0 g of a $$metal if the level of water in a graduated cylinder rises from $$25.0 mL to$$ $$33.0 mL $$after the metal is added?

Accepted Answer

$$6.0$$ $$g/cm^3$

Question 14

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

Accepted Answer

Micro ($$\mu)$$

Question 15

A $$50.0 mL $$urine sample has a mass of $$50.7 g. $$What is the specific gravity of the urine?

Accepted Answer

$$1.01$$

Question 16

Which of the following is a measured number?

Accepted Answer

The length of a table measured with a ruler.

Question 17

When adding $$5.000 + 0.03 + 2.0$$, how many digits past the decimal place should the final answer have?

Accepted Answer

1

Question 18

Which of the following statements about significant figures is TRUE?

Accepted Answer

Trailing zeros with a decimal point are significant.

Question 19

If you need to convert $$7.25$$ days to seconds, which conversion factors would you use?

Accepted Answer

$$1\ 	ext{day} = 24\ 	ext{hours},\ 1\ 	ext{hour} = 60\ 	ext{minutes},\ 1\ 	ext{minute} = 60\ 	ext{seconds}$$

Question 20

Which of the following is a real-life application of chemistry?

Accepted Answer

Baking bread

Chemistry Fundamentals: Measurements, Significant Figures, and Density

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