CHE 110

Chapter 1

100

Determine the number of significant figures of 0.0580 m³

Three

200

Convert 77K, the boiling point of liquid nitrogen, to degrees Celsius

-196.15^OC

300

The density of platinum is 21.45 g/cm³. What is the volume of a platinum sample with a mass of 11.2 g?

0.522 cm³

400

Four mass measurements of a metal cube were made using a laboratory balance. The results are 24.02 g, 23.99 g, 23.98 g, and 23.97 g. The actual mass of the metal cube is 25.00 g. Are the mass measurements accurate? Are the mass measurements precise?

Accurate: No
Precise: Yes

500

What is the volume in L of a 1.24 kg sample of benzene (density = 0.876 g/mL)?

1.42 L

Chapter 2

100

Write the formula for the molecular compound: sulfur tetrafluoride

SF₄

200

Calculate the number of neutrons in ²³⁹Pu

145

300

What is the empirical formula for caffeine (C₈H₁₀N₄O₂), a stimulant found in tea and coffee?

C₄H₅N₂O

400

Give the number of protons and electrons of Mn²⁺

Protons: 25
Electrons: 23

500

What is the symbol and charge for an ion containing 24 protons and 22 electrons?

Cr²⁺

Chapter 3

100

What is the molecular mass of citric acid, H₃C₆H₅O₇?

192.12 amu

200

How many moles of magnesium (Mg) are there in 87.3g of Mg?

3.59 moles

300

Calculate the number of moles of chloroform (CHCl₃) in 198 g of chloroform?

1.66 moles

400

Determine which of the following contains the largest numbers of atoms:

7.68 g of He
112 g of Fe
389 g of Hg

112 g of Fe

500

How many oxygen atoms are in 124 g of calcium phosphate, Ca₃(PO₄)₂?

1.93 x 10²⁴ O atoms