EXP. 1

Question 1

may be defined as the ratio of the
mass of a substance to the mass of an equal volume
of another substance taken as the standard.

Answer 1

SPECIFIC GRAVITY

Question 2

For gases, the standard may be ____/_____; for
liquids and solids, it is ____.

Answer 2

hydrogen or air

water

Question 3

True or False

The principle underlying the determination of the specific
gravity of either a liquid or a solid is the same: to find the ratio of
the mass (weight) of the substance to that of an equal density
of water

Answer 3

False- Density->Volume

Question 4

Specific Gravity is expressed as?

Answer 4

Ws/Ww

Question 5

is a factor that expresses how much
heavier or lighter a substance is – when compared to the
standard (water).

Answer 5

SPECIFIC GRAVITY

Question 6

sometimes called absolute specific gravity, is
used if the masses are determined in, or referred to, a vacuum.

Answer 6

True specific gravity

Question 7

True specific gravity is also called

Answer 7

Absolute Specific Gravity

Question 8

the calculated result if the masses are
determined in air.

Answer 8

Apparent specific gravity

Question 9

True or False

The difference between these specific gravities is, as a rule, very small.

Answer 9

True

Question 10

Liquids that are lighter than
water have a specific gravity?

Answer 10

less than 1

Question 11

those heavier
than water have a specific
gravity?

Answer 11

greater than 1

Question 12

The common practice with regard to the determination
of specific gravity is that defined by the USP:

Answer 12

Unless
otherwise stated, the specific gravity basis is 25°
/25°
,
ie, the ratio of the weight of a substance in air at 25°
to
that of an equal volume of water at the same
temperature.”

Question 13

is solid at 25°, the specific gravity
is determined on 100°/25° basis

Answer 13

Theobroma Oil

Question 14

Theobroma oil, which is solid at ____°, the specific gravity
is determined on _____ basis

Answer 14

25

100°/25°

Question 15

it is determined on a 15.56°/15.56° basis
because many years ago the US government adopted
60°F (15.56°C)

Answer 15

Alcohol

Question 16

Alcohol, it is determined on a ______ basis
because many years ago the US government adopted
______ as the temperature at which
_____measurements are to be made for
government control of alcoholic liquids.

Answer 16

15.56°/15.56°

60°F (15.56°C)

alcoholometric

Question 17

is a glass flask with a close-
fitting ground glass stopper with a capillary
hole through it.

Answer 17

PYCNOMETER

Question 18

A pycnometer is a special glass bottle used to determine specific gravity.
Generally available for laboratory use in volumes ranging from _____.

Answer 18

1 mL to 50 mL

Question 19

The Westphal Balance was first described
by German chemist _____
in _____

Answer 19

Carl Friedrich Mohr 1832

Question 20

Westphal Balance:

Modifications were made by the good _____ who replaced a _____
with an _____.

Answer 20

Dr.
Westphal

tray method

adjustable arm counterweight

Question 21

Westphal Balance is A.K.A.

Answer 21

Mohr Westphal Balance

Question 22

A direct-reading instrument for
determining the densities of solids
and liquids; a _____ of known
mass is immersed in the liquid whose
density is to be measured.

Answer 22

Westphal Balance

plummet

Question 23

WESTPHAL BALANCE relies on______ and
is balanced by an array of horseshoe-shaped
______ which come in _____,____,_____,_____ masses.

Answer 23

Archimedes’ Principle of buoyancy

counterweights/riders

5 g, 0.5 g, 0.05 g, and 0.005
g

Question 24

respectively signify the ones place of the specific gravity
of the sample solution, the tenths place, the hundredths
place, and the thousandths place.

Answer 24

counterweights (sometimes called riders)

Question 25

The numerical value each rider represents is equal to the numbered ______ which it sits in when the scale is balanced.

Answer 25

notch of the arm

Question 26

True or False The Westphal Balance is capable of highly accurate density readings

Answer 26

False- capable->incapable

Question 27

For extremely accurate density readings one may prefer to use a _____ although for speed and ease of use a _____ can quickly provide a very close approximation to the true density of any liquid solution.

Answer 27

pycnometer & Westphal

Question 28

is an instrument used for determining the specific gravity of liquids.

Answer 28

hydrometer

Question 29

is usually made of glass and consists of a cylindrical stem and a bulb weighted with mercury or lead shot to make it float upright.

Answer 29

hydrometer

Question 30

Parts of the Westphal Balance:

Answer 30

1. Balance Beam 2. Transverse notch scale 3. Stationary counterweight 4. Balance indicator scale 5. Glass float 6. Riders 7. Vessel with liquid 8. Thermometer 9. Double Pan 9.a. Upper Pan (solid brass) 9.b. Lower Pan (glass or aluminum w/ openings)

Question 31

The function of the hydrometer is based on

Answer 31

Archimedes’ principle

Question 32

Thus, the lower the density of the substance, the _____ the hydrometer will sink.

Answer 32

lower

Question 33

Hydrometers can be divided into two general classes:

Answer 33

liquids heavier than water and liquids lighter than water

Question 34

In the standard hydrometer scale, known as the specific gravity scale, distilled water equals ______, the initial point of measurement.

Answer 34

1.000

Question 35

Liquids lighter than water are scaled ____ 1.000 specific gravity, and liquids heavier than water are scaled _____ 1.000 specific gravity.

Answer 35

below; above

Question 36

for liquids heavier than water.

Answer 36

Heavy Hydrometer

Question 37

liquids lighter than water.

Answer 37

Light Hydrometer