The number with a lower value is the number of protons and the number with a higher value is the mass
The original or accepted value for the percent by mass of water in a hydrate = 36%
Percen by mass of water in the hydrate determined by the student
in the laboratory = 37.8%
So the difference between the actual and the percent by mass in water determined by student = (37.8 - 36.0)%
= 1.8%
So the percentage of error made by the student = (1.8/36) * 100 percent
= (18/360) * 100 percent
= ( 1/20) * 100 percent
= 5 percent
So the student makes an error of 5%. Option "1" is the correct option.
To determine the masses of each component, we need to know the concentration first in terms of molality which is mol per mass of solution. Assuming the density of the solution is equal to that of water we would find:
molality = 0.160 mol KBr / L ( 1 L / 1 kg solution ) = 0.160 mol KBr / kg solution
mass KBr = 0.160 mol KBr / kg solution (.0750 kg solution ) ( 119 g KBr / mol KBr ) = 1.428 g KBr
mass solvent = 75 - 1.428 = 73.572 g water
There's a lot of things built from petroleum, such as toothpaste.
Here's also another list.Gasoline 46%
Heating Oil / Diesel Fuel 20%
Jet Fuel ( kerosene) 8%
Propane / Propylene 7%
NGL / LRG 6%
Still Gas 4%
Petrochemical Feedstocks 2%
Petroleum Coke 2%
Residual / Heavy Fuel Oil 2%
Asphalt / Road Oil 2%
Lubricants 1%
Miscellaneous Products / Special Naphthas 0.4%
Other Liquids 1%
Aviation Gasoline 0.1%
Waxes 0.04%
Kerosene 0.02%
Gravel and sand are the most permeable, making them good aquifer materials. Gravel has the highest.
