Answer:
3.14
Explanation:
A student was comparing two samples with an equal number of carbon atoms. One sample contained only Carbon-12 atoms. One sample contained only Carbon-14 atoms, which contain two more neutrons than Carbon-12 atoms. The student measured the mass of each sample and testing the reactivity of each sample.
Required:
What would best describe the results of the investigation?
1) 1.8 micrograms(least)
2) 1.8 grams
3) 1.8 kilograms(greatest)
Answer:
Explanation:
The names Px, Py and Pz, indicate the orientation of the orbital in space. The key difference between Px Py and Pz orbitals is that Px orbital has two lobes oriented along the x-axis and Py orbital has two lobes oriented along the y-axis whereas Pz orbital has two lobes oriented along the z-axis.
We know that:
number of moles (n) = mass / molar mass
Now, from the general law of gases:
PV = nRT
where:
P is the pressure = 500 torr = 0.65 atm
V is the volume
n is the number of moles
R is the gas constant = 0.082
T is the temperature = 300 k
We will just rearrange this equation as follows:
P = nRT / V
Then we will substitute n with its equivalent equation mentioned at the beginning:
P = (mass x R x T) / (volume x molar mass) ......> equation I
Now, we know that:
density = mass / volume
We will substitute (mass/volume) in equation I with density as follows:
P = (density x R x T) / molar mass
Rearrange this equation to get the mass as follows:
molar mass = <span>dRT/P = (0.216 x 0.082 x 300) / 0.65 = 8.4738 grams
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From the periodic table:
molecular mass of hydrogen = 1 grams
molecular mass of nitrogen = 14 grams
Therefore:
molar mass of hydrogen = 2 x 1 = 2 grams
molar mass of nitrogen = 2 x 14 = 28 grams
We can assume that the number of moles of of each element is y.
We can thus build up the following equation:
2y + 28y = 8.4738
30y = 8.4738
y = 0.28246
Therefore:
mole fraction of hydrogen = 2 x 0.28246 = 0.56492
mole fraction of nitrogen = 28 x 0.28246 = 7.90888
The answer is; C
Conservation of matter in a reaction means that the mass of matter in the products is equal to the mass of the reactants. Energy/matter cannot be created or destroyed but converted from one form to another.
An expanding balloon with the increased evolution of gas is a good visible practical sign in the experiment on the conservation of matter in the reaction. As the magnesium disappears with an increased input of hydrochloric acid, the balloon gets bigger showing that more hydrogen is evolved from the reaction;
2HCL + Mg MgCl2 + H2