First, calculate for the mass of the aqueous solution by multiplying the given volume (in mL) by the density (in g/mL). In mathematical equation, that is,
m = ρV
where m is mass, ρ is density, and V is volume. Substituting the known values,
m = (1.03 g/mL)(250 mL) = 257.5 g
To get the concentration in ppm, divide the given mass of methanol by the mass of the solution. Note that the parts-per million (ppm) is equal to mass of solute in milligram(mg) divided by the mass of solution in kilogram (kg)
C (in ppm) = (1.56 x 10^-6 g)(1000 mg/1 g) / (257.5 g)(1 kg/1000 g)
Simplifying,
C (in ppm) = (1.56 x 10^-3 mg)/ 0.2575 kg
C (in ppm) = 0.00606 ppm
<em>Answer: 0.00606 ppm</em>
Answer:The Upper Paleolithic period started about 40,000 years BC and ended about 10,000 years BC. So it took place between 40,000 and 10,000 BC. After that started the Mesolithic Era ( 10,000 to 4,000 BC ). Stone tools in the Upper Paleolithic period were primarly blade-based technology. Also this period is well known for the cave art and paintings of animals. Answer: C ) The period took place between 40,000 and 4,000 BC ( not true ).
Explanation:
Heterogeneous Mixtures aren't uniform and are separated in the mixture. They are usually more easily able to be separated. An example is milk and cereal. The cereal isn't uniform because the milk and cereal still are separated and have their own identities. (You can easily just remove cereal from milk using a strainer)
Homogeneous Mixtures are uniform in composition and the multiple elements have become one solution. These mixtures are hard to separate into their components. An example is tap water because it contains water as well as various minerals that can only be separated by performing chemical reactions.
Part (a): The masses
From the periodic table:
molar mass of copper = 63.5 grams
This means that:
mass of 2..06 moles = 2.06 * 63.5 = 130.81 grams
comparing this mass with the 222 grams of silver, we will find that the mass of silver is greater.
Part (b): The atoms:
number of moles = mass / molar mass
number of moles of silver = 222 / 107.8 = 2.059 moles
each mole contains Avogadro's number of atoms.
Since number of moles of copper is slightly larger than nuber of moles of silver, this means that the number of atoms in the copper sample would be more.
