Chapter 9: Calculations Used In Analytical Chemistry

Question 1

Physical quantity: Mass
SI Base Unit:

Answer 1

kilogram, kg

Question 2

Physical quantity: Length
SI Base Unit:

Answer 2

meter, m

Question 3

Physical quantity: time
SI Base Unit:

Answer 3

Second, s

Question 4

Physical quantity: temperature
SI Base Unit:

Answer 4

Kelvin, K

Question 5

Physical quantity: amount of substance
SI Base Unit:

Answer 5

mole, mol

Question 6

Physical quantity: electric current
SI Base Unit:

Answer 6

Ampere, A

Question 7

Physical quantity: luminous intensity
SI Base Unit:

Answer 7

Candela, cd

Question 8

• a method to measure how much a chemical substance absorbs light by measuring the intensity of light as a beam of light passes through sample solution.
• The basic principle is that each compound absorbs or transmits light over a certain range of wavelength.

Answer 8

spectrophotometry

Question 9

Visible light has a wavelength between

Answer 9

~400 nm - ~700 nm

Question 10

an unchanging measure of the quantity of matter.

Answer 10

mass, m

Question 11

the force of gravitational attraction between that matter and Earth.

Answer 11

weight, w

Question 12

A chemical analysis is always based on __ so that the results will not depend on locality.

Answer 12

mass

Question 13

are precision weights used to calibrate weighing instruments and ensure accurate measurements.

Answer 13

Calibration weights

Question 14

mole

Answer 14

6.022 x 10^23 atoms/ions/molecules/electrons/entities

Question 15

four fundamental ways of expressing
solution concentration:

Answer 15

• Molar concentration
• Percent concentration
• Solution-diluent volume ratio
• p-functions

Question 16

a solution of a solute species X is the number of moles of that species that is contained in 1 L of the solution (not 1 L of the solvent).

Answer 16

molar concentration cx

Question 17

1M = ______ = 1 mol/L = ____ = ____

Answer 17

= 1 mol L^-1
= 1mmol L^-1
= 1 mmol/1 mL

Question 18

three common methods in percent concentration

Answer 18

• weight percent (w/w)
• volume percent (v/v)
• weight/volume percent (w/v)

Question 19

expressions do not depend on the units used for weight (mass) or volume as long as the same units are used in the numerator and the denominator.

Answer 19

• weight percent (w/w)
• volume percent (v/v)

Question 20

Of the three expressions, only __ __ has the advantage of being temperature independent.

Answer 20

weight percent

Question 21

The composition of a dilute solution is sometimes specified in terms of the volume of a more concentrated solution and the volume of solvent used in diluting it.

Answer 21

Solution-Diluent Volume Ratios

Question 22

the negative logarithm (to the base 10) of the molar concentration of that species. Thus, for the species X, pX=-log[X]

Answer 22

p-function or p-value

Question 23

p-function or p-value formula

Answer 23

pX= -log [X]

Question 24

a substance is its mass per unit volume (kg/L or g/mL)

Answer 24

density

Question 25

the ratio of its mass to the mass of an equal volume of water at 4°C (dimensionless)

Answer 25

specific gravity

Question 26

the quantitative relationship among the amounts of reacting chemical species.

Answer 26

stoichiometry