Physics Exp 2
3
Group # 5 2AMT Date performed: June 30, 3011 Members: Date submitted: July 7, 2011 EXPERIMENT # 2 <SPECIFIC GRAVITY AND RELATIVE DENSITY> Abstract The aim of the experiment is to discover how to use the Pycnometer in determining the specific gravity of a sample solid, and sample liquid, and to relate the following equations, Specificgravity = mass of sample liquid mass of water , and Specificgravity = mass of sample solid mass of displaced liquid for it. Thorough reading of the triple beam balance, Mohr-Westphal balance, Baume hydrometer, Leach Pycnometer, and Pycnometer scales, accurate computations and respect to the formulas, and mastery of the strict rule of significant figures are needed in this experiment. Specific gravity is the ratio of the density of any substance to the density of some other substance taken as standard, water being the standard for liquids and solids, and hydrogen or air being the standard for gases. The group is provided with CuSO 4 for the sample solid, and alcohol for the sample liquid. The group first determined the mass of the empty pycnometer, the pycnometer with water, the pycnometer with the liquid sample/solid sample, the water, and the liquid/solid sample and related them into the equations to find out the specific gravity. Question and Answer 1. Differentiate specific gravity and density. Density is defined as mass per unit volume; it has the SI unit kg·m -3 and is an absolute quantity. Specific gravity is the ratio of a material's density with that of water at 4 °C. 2. If 54.96ml of oil weighs 52.78g, what is its specific gravity? Specificgravity = 52.78 g 54.96 ml Specificgravity =0.9603 3. A pycnometer weighs 50.00g. When filled with water, it weighs 100.00g. When filled with oil, it weighs 94.00g. Determine the specific gravity of the oil.
Transcript of Physics Exp 2
Group # 5 2AMT Date performed: June 30, 3011Members: Date submitted: July 7, 2011
EXPERIMENT # 2 <SPECIFIC GRAVITY AND RELATIVE DENSITY>
AbstractThe aim of the experiment is to discover how to use the Pycnometer in determining the specific
gravity of a sample solid, and sample liquid, and to relate the following equations,
Specific gravity=massof sample liquidmassof water
, and Specific gravity= mass of sample solidmassof displaced liquid
for it.
Thorough reading of the triple beam balance, Mohr-Westphal balance, Baume hydrometer, Leach Pycnometer, and Pycnometer scales, accurate computations and respect to the formulas, and mastery of the strict rule of significant figures are needed in this experiment. Specific gravity is the ratio of the density of any substance to the density of some other substance taken as standard, water being the standard for liquids and solids, and hydrogen or air being the standard for gases. The group is provided with CuSO4 for the sample solid, and alcohol for the sample liquid. The group first determined the mass of the empty pycnometer, the pycnometer with water, the pycnometer with the liquid sample/solid sample, the water, and the liquid/solid sample and related them into the equations to find out the specific gravity.
Question and Answer1. Differentiate specific gravity and density.
Density is defined as mass per unit volume; it has the SI unit kg·m-3 and is an absolute quantity. Specific gravity is the ratio of a material's density with that of water at 4 °C.
2. If 54.96ml of oil weighs 52.78g, what is its specific gravity?
Specific gravity= 52.78 g54.96ml
Specific gravity=0.9603
3. A pycnometer weighs 50.00g. When filled with water, it weighs 100.00g. When filled with oil, it weighs 94.00g. Determine the specific gravity of the oil.
Mass of empty pycnometer=50.00 g(A)Mass of pycnometer+water=100.00 g(B) Mass of pynometer+oil=94.00 g(C )Mass of water=100.00g (B )−50.00g ( A )Mass of water=50.00gMass of oil=94.00 g(C)−50.00g (A )Mass of oil=44.00 g
Specific gravity=massof sample liquidmassof water
Specific gravity=44.00g50.00g
Specific gravity of the oil=0.8800
4. An insoluble powder weighs 12.00g. A pycnometer, weighing 21.00g when empty, weighs 121.00g when filled with water. When the powder is introduced into the emptied pynometer, the pycnometer is filled with water. The three together weigh 130.00g. What is the specific gravity of the powder?
Mass of empty pycnometer=21.00 g ( A )Mass of pycnometer+water=121.00 g (B )Mass of pycnometer+ powder=21.00 g+12.00g=33.00 g(C )Mass of pycnometer+ powder+water=130.00g (D )
Specific gravity= mass of powdermassof displaced liquid
Specific gravity=(C )−(A)
(B−A )−(D−C )
Specific gravity=33.00 g (C )−21.00g ( A )
(121.00g (B )−21.00 g ( A ) )−(130.00 g (D )−33.00 g (C ))
Specific gravity= 12.00g100.00 g−97.00 g
Specific gravity=12.00 g3.00 g
Specific gravity of the powder=4.00
Reference:Physics Laboratory Noteshttp://www.npl.co.uk/reference/faqs/what-is-the-difference-between-density-and-specific-gravity-(faq-mass-and-density)http://dictionary.reference.com/browse/specific+gravity
