Chemical measurements

Question 1

Orders of magnitude

Answer 1

(powers of ten)

Question 2

SI units for

• Time
• Mass
• Electric current
• Luminous intensity
• Amount of substance
• Plane angle
• Solid angle

Answer 2

SI units for

• Time: second (s)
• Mass: kilogram (kg)
• Electric current: ampere (A)
• Luminous intensity: candela (cd)
• Amount of substance: mole (mol)
• Plane angle: radian (rad)
• Solid angle: steradian (sr)

Question 3

Prefix

• Giga: G
• Meta: M
• kilo: k
• deci: d
• centi: c
• mili: m
• micro:
• nano: n
• pico: p

Answer 3

Prefix

• Giga: G (10^9)
• Meta: M (10^6)
• kilo: k
• deci: d
• centi: c
• mili: m
• micro:
• nano: n
• pico: p

Question 4

Solute

Answer 4

minor species in a solution

Question 5

Solvent

Answer 5

major species in a solution

Question 6

Concentration

Answer 6

how much solute is contained in a given volume or mass

Question 7

Molarity (M)

Answer 7

number of moles of a substance per liter of solution

Question 8

mole

Answer 8

Avogadro’s number of atoms or molecules or ions (6.022*10^23 1/mol)

Question 9

Liter (L)

Answer 9

volume of a cube that is 10 cm on each edge

Question 10

atomic mass

Answer 10

atomic mass of an element is the number of grams containing Avogadro’s number of the atoms in the molecule

Question 11

strong electrolyte

Answer 11

mostly dissociated into ions in solution

Question 12

weak electrolyte

Answer 12

partially dissociated into ions in solution

Question 13

formal concentration (F)

Answer 13

molarity of strong electrolyte

Question 14

formula mass (FM)

Answer 14

“molecular mass” of a strong electrolyte = sum of atomic masses in the formula

Question 15

molality (m)

Answer 15

concentration = (number of moles of a solute)/(kilogram of solvent)

Question 16

If no evaporation, do molality change with temperature?

Answer 16

No because m=concentration of masses

masses of solute & solvent X change when no evaporation

Question 17

Do molarity change with temperature?

Answer 17

volume solution increase when heated

M = mol/V

Question 18

weight percent (wt%)

Answer 18

percentage of a component in a mixture or solution

wt% = 100*(mass of solute)/(mass of total solution or mixture)

Question 19

volume percent (vol%)

Answer 19

volume percent = 100*(volume of solute)/(volume of total solution)