Answer : 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
Solution : Given,
Mass of Cu = 300 g
Molar mass of Cu = 63.546 g/mole
Molar mass of
= 183.511 g/mole
- First we have to calculate the moles of Cu.

The moles of Cu = 4.7209 moles
From the given chemical formula,
we conclude that the each mole of compound contain one mole of Cu.
So, The moles of Cu = Moles of
= 4.4209 moles
- Now we have to calculate the mass of
.
Mass of
= Moles of
× Molar mass of
= 4.4209 moles × 183.511 g/mole = 866.337 g
Mass of
= 866.337 g = 0.8663 Kg (1 Kg = 1000 g)
Therefore, 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
Answer: D. They show that neither theory is complete and entirely correct.
Explanation:
Theory is the set of rules and principles that describe and explain a particular phenomenon (the existence of the moon in this case) and is subject to changes as new evidence emerges that gives meaning to it.
In this sense, there are many theories about the Earth's moon formation and two of the "accepted" theories are described before the question. In addition, both theories explain in a certain way the reason why the Moon is predominantly composed of elements similar to those found on Earth.
However, both theories seem to be incomplete when trying to explain our Moon's origin.
This problem has two parts; the first one asking for the concentration of NaBr given both its mass and volume and the second one asking for its volume given both mass and concentration. The answers turn out to be 0.158 M and 211 mL.
<h3>Molarity</h3>
In chemistry, the use of units of concentration depends on both the substances to analyze and their amounts. In such a way, for molarity, one needs the following relationship between the moles of solute and volume of solution:

Thus, for the first part of the problem we first calculate the moles in 2.60 g of NaBr via its molar mass:

Next, we convert the 160. mL to L by dividing by 1000 in order to obtain 0.160 L to subsequently calculate the molarity:

Next, since the moles remain the same and for the second part we are asked for the volume given the concentration, one can solve for the volume so as to obtain:

That in milliliters turns out to be:

Learn more about molarity: brainly.com/question/10053901
That's because the solubility
- Temperature is directly proportional to solubility
Higher the solubility higher the temperature
Lower the temperature lower the solubility
So
Less temperature makes enzymes work faster