Q: A sample contains 0.005 kilometers. Convert this distance to meters using SI prefixes.

$$0.005 \times 10^3$ = 5$$ meters

Q: A scientist needs to convert 250 milligrams to kilograms. Which calculation is correct?

$$250 \times 10$$^{-6}$$ = 0.00025 kg$$

Q: If the density of vanadium is $$6.96 \ \mathrm{g/cm^3$}$$, what is its density in $$\mathrm{kg/m^3$}$$?

$$6.96 \ \mathrm{g/cm^3$} \times \frac{1 \ \mathrm{kg}}{1000 \ \mathrm{g}} \times \frac{10^6$ \ \mathrm{cm^3$}}{1 \ \mathrm{m^3$}} = 6960 \ \mathrm{kg/m^3$}$$

Q: If the flow rate of the Niagara River is $$3.50 \ \mathrm{km^3$/year}$$, what is the flow rate in liters per second? (1 $$\mathrm{km^3$}$$ = $$10^{12} L$$, 1 year = $$3.15 \times 10^7$ s)

$$\frac{3.50 \times 10$$^{12}$$ \ \mathrm{L}}{3.15 \times 10^7$ \ \mathrm{s}} \approx 1.11 \times 10^5$ \ \mathrm{L/s}$$

Question 1

Which of the following is the correct SI base unit and symbol for measuring electric current?

Accepted Answer

Ampere, A

Question 2

A sample contains 0.005 kilometers. Convert this distance to meters using SI prefixes.

Accepted Answer

$$0.005 	imes 10^3$ = 5$$ meters

Question 3

Which of the following polyatomic ions has the formula $$\mathrm{CO_3$^{2-}}$$?

Accepted Answer

Carbonate

Question 4

What is the correct name for the acid $$\mathrm{H_2SO_4}$$?

Accepted Answer

Sulfuric acid

Question 5

A scientist needs to convert 250 milligrams to kilograms. Which calculation is correct?

Accepted Answer

$$250 	imes 10$$^{-6}$$ = 0.00025 kg$$

Question 6

Which law states that a chemical compound always contains exactly the same proportion of elements by mass?

Accepted Answer

Law of Definite Proportions

Question 7

If the density of vanadium is $$6.96 \ \mathrm{g/cm^3$}$$, what is its density in $$\mathrm{kg/m^3$}$$?

Accepted Answer

$$6.96 \ \mathrm{g/cm^3$} 	imes \frac{1 \ \mathrm{kg}}{1000 \ \mathrm{g}} 	imes \frac{10^6$ \ \mathrm{cm^3$}}{1 \ \mathrm{m^3$}} = 6960 \ \mathrm{kg/m^3$}$$

Question 8

Which of the following is the correct formula for the nitrite ion?

Accepted Answer

$$\mathrm{NO_2$^-}$$

Question 9

A chemical reaction is balanced when:

Accepted Answer

The number of atoms of each element is the same on both sides of the equation

Question 10

Which SI prefix represents a multiplication factor of $$10^{-9}$$?

Accepted Answer

nano

Question 11

If the flow rate of the Niagara River is $$3.50 \ \mathrm{km^3$/year}$$, what is the flow rate in liters per second? (1 $$\mathrm{km^3$}$$ = $$10^{12} L$$, 1 year = $$3.15 	imes 10^7$ s)

Accepted Answer

$$\frac{3.50 	imes 10$$^{12}$$ \ \mathrm{L}}{3.15 	imes 10^7$ \ \mathrm{s}} \approx 1.11 	imes 10^5$ \ \mathrm{L/s}$$

Question 12

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

Accepted Answer

$$\mathrm{OH^-}$$

Question 13

Which acid is formed from the chlorate ion?

Accepted Answer

Chloric acid ($$\mathrm{$$HClO_3$$})$$

Question 14

A solution contains $$1.25 \ \mathrm{g} of $$nitrogen gas at STP and occupies $$1.00 \ \mathrm{L}. $$What is the density of nitrogen gas at STP?

Accepted Answer

$$\frac{1.25 \ \mathrm{g}}{1.00 \ \mathrm{L}} = 1.25 \ \mathrm{g/L}$$

Question 15

Which of the following is the correct SI prefix and multiplication factor for 'micro'?

Accepted Answer

micro, $$10^{-6}$$

Question 16

Which of the following is the correct formula for the phosphate ion?

Accepted Answer

$$\mathrm{PO_4$^{3-}}$$

Question 17

A student needs to convert 3.785 liters to gallons. Which calculation is correct? (1 gallon = 3.785 liters)

Accepted Answer

$$\frac{3.785 \ \mathrm{L}}{3.785 \ \mathrm{L/gallon}} = 1$$ gallon

Question 18

Which of the following is the correct formula for the nitrate ion?

Accepted Answer

$$\mathrm{NO_3$^-}$$

Question 19

Which of the following is the correct name for $$\mathrm{H_3PO_4}$$?

Accepted Answer

Phosphoric acid

CHEM 1321: Introduction to Chemistry – Units, Prefixes, Polyatomic Ions, and Dimensional Analysis

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