Which of the following is used as a refrigerant? methane esters freon fluorine

9. Using the balanced equation from Question #8, how many grams of lead will be produced if 2.54 grams of PbS is burned with 1.8

MissTica

Answer: 2.24 grams of Pb

Explanation:

Step 1

Balanced chemical reaction;

2PbS + 3O2 → 2Pb + 2SO3

Step 2

Moles of both PbS and O2

Moles = mass / molar mass

Moles of PbS = 2.54 g / 239.3 g/mol = 0.0108 moles

Moles of O2 = 1.88 / 32 g/mol = 0.0588 moles

Step 3

Finding the limiting reactant.

Limiting reactant, is that reactant which is completely used in the reaction;

If we assume that PbS is the limiting reactant;

We have 0.0588 moles of O2. This needs ( 0.0588 * 2) / 3 = 0.0392 moles of PbS to fully react. But we have only 0.0108 moles of PbS available. That means that the PbS will be completely consumed hence the limiting reactant

If we assume O2 is the limiting reactant;

We have 0.0108 moles of PbS. That needs ( 0.0108 * 3) / 2 = 0.0162 moles of O2. But we have 0.0588 moles of O2 which is in excess further confirming that PbS is the limiting reactant since it will be depleted in the reaction.

Step 4

Moles of lead

For this step we apply the mole ratios with the limiting reactant;

Mole ratio of PbS : Pb = 2 : 2 = 1 : 1

Therefore;

Moles of Pb = (0.0108 moles * 1 ) 1

Moles of Pb =0.0108 moles

Step 5

Mass of Pb

Mass = moles * molar mass

Mass of Pb =0.0108 moles * 207.2 g/mol

Mass of Pb = 2.24 grams

5 0

3 years ago

Your apple juice has a molarity of 3.4 M and a volume of 0.895 litres. What does a student have to do to decrease the molarity t

Jlenok [28]

Answer:

4.285 L of water must be added.

Explanation:

Hello there!

In this case, for this dilution-like problems, we need to figure out the final volume of the resulting solution so that we would be able to obtain the correct volume of diluent (water) to be added. In such a way, we can obtain the final volume, V2, as shown below:

$M_1V_1=M_2V_2\\\\V_2=\frac{M_1V_1}{M_2}$

Thus, by plugging in the initial molarity, initial volume and final molarity (0.587 M) we obtain:

$V_2=\frac{3.4M*0.895 L}{0.587M}\\\\V_2=5.18L$

It means we need to add:

$V_{H_2O} ^{added}=5.18L-0.895L=4.285L$

Of diluent water.

Regards!

6 0

3 years ago

Ion arrangements of three general salts are represented below. h5sil917 h5sil917021 h5sil91703 which ion arrangement has the hig

vovangra [49]

This question is incomplete. Luckily, I found the same problem which is shown in the attached picture. To answer the question, we must know how the size and charge affect the lattice energy. The answer is: lattice energy increases with the increasing charge of the ions, and decreasing radius of the atoms. Therefore, the ranking would be: A .

4 0

3 years ago

Select the correct answer.

bazaltina [42]

C. Magma from venus mantle erupted as lava.

Explanation:

A volcano is a land form which results from the eruption of molten rocks (lava) on the surface. Volcanic rocks are a special type of igneous rock that forms when molten rock cools and solidifies on the surface.

For a planet like Venus which is presently not active and little to no movement occurs within the plates, the volcanisim must have occurred when the planet was relatively young and it must have been millions of years ago.

It is widely believed that Venus was geologically active in times past. Mantle generated lava must have solidified on the surface in times past to have formed the volcano.

Evaluating other options:

Impact of space objects on Venus would lead to the formation of a crater which is a depression on the surface. The rock would be mostly metamorphic.

If water was ever present in Venus, they would have produced sedimentary rocks instead. The erosive power of water is not high enough to cut through the crust. Also, water would not aid the formation of volcanoes.

Heat is not enough to from volcanoes. Other factors are also in play.

5 0

3 years ago

Example of market structures of monopoly

IgorC [24]

Answer: A monopoly is the absence of competition in the market.

Explanation:

In such circumstances, the market creates a monopoly of one producer who takes huge capital and dictates prices. An example of a monopoly on the market is the existence of only one company that makes up the entire economic branch. In such circumstances, the monopolist can increase the product's price without losing the entire sale, i.e., operating successfully. In that situation, the monopolist remains the only one on the market, and the competition has no access to the market.

8 0

3 years ago