The answer is 27.8 grams of PbS must have reacted to produce 765 kJ of heat. The first step in solving this problem is to use the given enthalpy change and the stoichiometry of the reaction to determine the amount of heat produced when one mole of PbS reacts.
We can do this by using the following formula: ΔH_rxn/mol = ΔH_rxn/2 mol PbS = -827.4 kJ/mol / 2 mol PbS. ΔH_rxn/mol = -413.7 kJ/mol PbS. This means that for every mole of PbS that reacts, 413.7 kJ of heat is produced. Next, we can use the amount of heat produced in the reaction (765 kJ) to calculate the amount of PbS that must have reacted. We can set up a proportion:
765 kJ / 413.7 kJ/mol = x mol PbS / molar mass of PbS
We can solve for x (the number of moles of PbS that reacted) by rearranging the equation:
x mol PbS = (765 kJ / 413.7 kJ/mol) * (1 / molar mass of PbS)
Using the molar mass of PbS (239.3 g/mol), we can calculate the number of moles of PbS that reacted:
x mol PbS = (765 kJ / 413.7 kJ/mol) * (1 / 239.3 g/mol) = 0.116 mol PbS
Finally, we can convert the number of moles of PbS to mass using its molar mass:
mass of PbS = 0.116 mol PbS * 239.3 g/mol = 27.8 g PbS
Therefore, 27.8 grams of PbS must have reacted to produce 765 kJ of heat.
For more questions like heat visit the link below:
https://brainly.com/question/31070620
#SPJ11
The equation below represents the process that you observed. Balance the equation. What type of reaction?
6CO2 + 6H2O + light energy = 0C6H12O6 + 6O2 _______________________
Answer:
Explanation:
6CO2 + 6H2O = 0C6H12O6 + 6O2
First you note how much u got of everything in front of and behind the arrow
C 6 C 6
O 6 + 12 = 18 O 6 + 12 = 18
H 12 H 12
As you can see, the equation is already balanced.
This is the equation of photosynthesis, which is a chemical reaction
Please help asap i really need it
Answer:
decomposers
Explanation:
is it multiple choice
I need help with this question ASAP
Answer:
I think its A)
Explanation: im not sure im sorry
What is the freezing point of a solution of 498mL of water (solute) dissolved in 2.50 L of ethanol (solvent), C2H5OH? The density of C2H5OH is 0.789g/cm3. (Remember that water has a density of 1.0 g/cm3.)
Answer:
Freezing T° of solution is -142.4°C
Explanation:
This excersise is about colligative properties, in this case freezing point depression,
ΔT = Kf . m . i
Where ΔT = Freezing T° of solvent - Freezing T° of solution
Kf = Cryoscopic constant
m = mol/kg (molality)
i = Number of ions dissolved.
Water is not ionic, so i = 1
Let's find out m.
We determine mass of water, by density
498ml . 1 g/mL = 498 g
We convert the mass of water to moles → 498 g . 1mol/18g = 27.6 moles
We determine mass of solvent by density
2500 mL . 0.789 g/mL = 1972.5 g
Notice, we had to convert L to mL to cancel units.
1 cm³ = 1 mL
We convert the mass from g to kg → 1972.5 g . 1kg /1000g = 1.97kg
We determine m = mol/kg → 27.6mol / 1.97kg = 13.9 m
Kf for ethanol is: 1.99 °C/m
Freezing T° for ethanol is: -114.6°C
We replace at formula: - 114.6°C - Freezing T° solution = 1.99 °C/m . 13.9 m . 1
- 114.6°C - Freezing T° solution = 27.8 °C
- Freezing T° solution = 27.8°C + 114.6°C
Freezing T° Solution = - 142.4 °C
Choose the aqueous solution below with the highest boiling point. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.
The question is incomplete, the complete question is;
Choose the aqueous solution that has the highest boiling point. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable. 0.100 m C6H12O6 0.100 m AlCl3 0.100 m NaCl 0.100 m MgCl2 They all have the same boiling point.
Answer:
AlCl3 0.100 m
Explanation:
Let us remember that the boiling point elevation is given by;
ΔTb = Kb m i
Where;
ΔTb = boiling point elevation
Kb = boiling point constant
m = molality of the solution
i = Van't Hoff factor
We can see from the question that all the solutions possess the same molality, ΔTb now depends on the value of the Van't Hoff factor which in turn depends on the number of particles in solution.
AlCl3 yields four particles in solution, hence ΔTb is highest for AlCl3 . The solution having the highest value of ΔTb also has the highest boiling point.
El oxígeno y el azufre reaccionan con el cobre para formar óxido de cobre (CuO) y sulfuro de cobre (CuS), respectivamente. ¿Qué cantidad de azufre reacciona con el oxígeno? 1° Cu + O2 =2CuO 2° Cu + S = CuS 3° S + O2 = 2SO
The given reaction is an example of displacement reaction. Here, one mole of oxygen reacts with one mole of oxygen molecules. Hence theoretically 32 g of sulphur needs 32 g of oxygen.
What is displacement reaction?Displacement reactions are a kind of reactions where one element or group is displaced with other element or group. There are both single displacement and double displacement reaction.
The reaction of sulfur oxide with metallic copper producing copper oxide and copper sulphide is an example of single displacement reaction. The prior reaction for this is the combination of sulfur and oxygen.
Here, one mole of oxygen reacts with one mole of oxygen molecules. Hence theoretically 32 g of sulphur needs 32 g of oxygen. Thus each is reacting in 1 :1 ratio and giving the oxide of sulfur.
To find more on displacement reaction, refer here:
https://brainly.com/question/29307794
#SPJ5
The English translation of your question is as follows:
Oxygen and sulfur react with copper to form copper oxide (CuO) and copper sulfide (CuS), respectively. How much sulfur reacts with oxygen? 1° Cu + O2 =2CuO 2° Cu + S = CuS 3° S + O2 = 2SO
How much 2.0 M NaCl solution would you need to make 250 mL of 0.15 M NaCl solution?
Answer:
18.75 mL
Explanation:
(M1)(V1)=(M2)(V2)
(2.0 M)(V1)=(0.15 M)(250 mL)
(2.0)(V1)=37.5
Divide 2.0 on both sides
V1=18.75 mL
Expressed to the correct number of significant figures, the sum of two masses is 445.2 grams. Which two masses produce this answer?
a) 210.10g+ 235.00g
b) 210.100g + 235.10g
c) 210.1g + 235.1g
d) 210.10g + 235.10g
Answer:
All except a
Explanation: I like math. Pls mark brainliest.
The two numbers presented in the options, B, C, and D give a sum of 445.2 grams. So the correct options are B, C, and D.
What are significant figures?The number that is given as digits is established using significant figures. A significant depiction of numbers is carried by these digits. Frequently, significant numbers are employed in place of figures. By counting all of the values beginning with the first non-zero digit on the left, we may determine the number of significant digits. 13.56, for instance, has four significant digits.
The crucial or key digits that accurately represent the meaning of a certain number are known as the significant figures of that number. 7.864 contains four significant digits, for instance. These huge amounts give the accuracy of the numbers. Additionally, they are known as important digits.
Therefore, the correct options are B, C, and D.
Read more about significant figures, here
https://brainly.com/question/14804345
#SPJ2
The ____________________ is an upward force exerted by a fluid on any object in the fluid. a. fluid pressure c. fluid force b. buoyant force d. Bernoulli force
Answer:
B. The Buoyant Force
Explanation:
'The Buoyant Force is an upward force exerted by a fluid on any object in the fluid.'
The name for a mixture in which all samples are made up of the same
proportions of matter is:
Answer: homogeneous mixture
Explanation:
A rain garden is a garden planted in a low-lying area where water tends to collect.
What benefit would rain gardens most likely provide for a community?
Predict: In each "Climate type" box, Highlight the condition you think will lead to the fastest weathering for the given weathering type.
Weathering type
Climate type
Frost wedging
Hot
Cold
Wet
Dry
Clay formation
Hot
Cold
Wet
Dry
Dissolving
Hot
Cold
Wet
Dry
Answer:
Frost Wedging - Hot and dry
Clay Formation - Cold and Wet
Dissolving - Cold, and dry
Explanation:
The frost wedging happen when the climatic condition is hot and dry. The dry weather compensates the heat and the rock wedging happens quickly. For clay formation the weather has to be cold and wet. The cold weather will make the sand indulge with rock particles resulting in the clay formation.
PLEASE HELP ANSWER ALL PARTS!!!
Answer:
The student should have multiplied the molar mass, which was not found, by the number of moles to get an answer of 925grams of Ca(OH)2.
Please find the correct step below
Explanation:
According to the question attached, the student was asked to find the mass in grams of a 12.5mol of Ca(OH)2.
Using the formula;
mole = mass ÷ molar mass
Molar mass of Ca(OH)2 = 40 + (16 + 1)2
= 40 + 17(2)
= 40 + 34
= 74g/mol
From the above formula;
Mass in grams = mole × molar mass
Mass (g) = 12.5 × 74
Mass (g) = 925grams of Ca(OH)2.
Which of the following may be a reason why climbing up objects would help the ivy survive?
What is the difference between fumarate and fumaric acid?
Answer:
the difference is fumaric acid the carboxylic acid groups are trans (E) and in maleic acid they are cis (Z)
Explanation:
and Fumarate is an intermediate in the citric acid cycle used by cells to produce energy in the form of adenosine triphosphate (ATP) from food
chemical composition of the gas in LPG cylinder??
LPG is composed hydrocarbons containing three or four carbon atoms. The normal components of LPG thus, are propane (C3H8) and butane (C4H10). Small concentrations of other hydrocarbons may also be present.
Can anyone help me with this assignment? Will give Brainliest.
Answer:
i cant get the pdf im so sorry
Explanation:
Answer:
Yes if u need help?
Explanation:
Question 5
4
What type of plate boundary involves plates moving away from each other?
convergent
divergent
transform
Answer:
A divergent boundary!
Explanation:
A divergent boundary occurs when two plates move away from each other, while a convergent boundary is when two plated collide. And a transform plate boundary is when two plates horizontally slide against each other.
I hope this helps! ^^
☁️☁️☁️☁️☁️☁️☁️
Answer:
The answer is Divergent boundaries
3 By referring to subatomic particles, explain why
an atom of
nitrogen is electrically neutral.
Answer:
Explained below
Explanation:
Atoms are said to be electrically neutral when they have the same number of protons and electrons.
Now, Nitrogen atom has a mass number of 14 and an atomic number of 7. This means that it has 7 number of protons and 7 number of electrons.
From the definition of electrically neutral atoms, it's clear that nitrogen falls into that category.
What are the sex cells of the plants that Mendel studied?
Answer:
alleles
Explanation:
Answer:
ghbdjdbdhdbdbdndjfbfnfnfjfbfjskssks
ijdij
Explanation:
jsjj
Can someone help me with my stoichiometry homework, it is due tonight.
Answer:
1. 1 mole of NaCl.
2. 1 mole of H₂O.
Explanation:
The balanced equation for the reaction is given below:
HCl + NaOH —> NaCl + H₂O
From the balanced equation above,
1 mole of HCl reacted with 1 mole of NaOH to produce 1 mole of NaCl and 1 mole of H₂O.
Next, we shall determine the limiting reactant. This can be obtained as follow:
From the balanced equation above, we can see that 1 mole of HCl reacted completely with 1 mole of NaOH. Therefore, HCl is the limiting reactant and NaOH is the excess reactant since we have 3.6 moles of NaOH.
1. Determination of the amount of NaCl produced from the reaction.
NOTE: The limiting reactant is used to determine the maximum amount produced since all of it is consumed in the reaction.
The limiting reactant is HCl and the amount of NaCl produced can be obtained as follow:
From the balanced equation above, we can see that 1 mole of HCl reacted to 1 mole of NaCl.
Thus, 1 mole of NaCl was produced.
2. Determination of the amount of H₂O produced from the reaction.
From the balanced equation above, it is evident that 1 mole of HCl reacted to produce 1 mole of H₂O.
Thus, 1 mole of H₂O was produced.
A quanta of electromagnetic energy is called *
Answer: A quantum of electromagnetic energy is called a photon. Also, do you mean a quantum because I don't think a quanta is a thing
Explanation:
Ummm help? From start to finish
Which of the following is a property of a non-metal.
luster
ductile
malleable
does not conduct heat and electricity
Answer:
luster
:/:/:/:/:::/:::
why an aspirin tablet works faster if it is crushed rather than swallowed whole?
Answer: because the tablet is already crushed and is easy for the organism to absorb instead of having to break it down
Explanation:
Mammals and plants do not belong in the same domain.
Fact:
Evidence:
False
Fact: Mammals and plants belong to the same domain, the Eukarya domain.
Evidence :All the organisms that possess a eukaryotic cell, plants, animals, protists, and fungi are in the Eukarya domain.
How many moles of water are contained in 3.58 x 10^24 molecules? 6.022
x 10^23 molecules = 1 mole
O 5.94 moles
0 10.0 moles
0 022 x 10^23 moles
0 3.00 moles
Answer:
Try everything
O 5.94 moles
0 10.0 moles
0 022 x 10^23 moles
0 3.00 moles
Explanation:
What is the name for: CO2?
AND
Describe the steps for how you determined this.
Answer:
carbon dioxide
C = carbon
O2 = dioxide
1s2, 2s2, 2p6, 3s2, 3p6, 4s2
How many shells does this atom have?
Answer:
4
Explanation:
Sharon puts a large pot of water on the stove to boil pasta. Then she starts to make a tomato sauce. When the sauce is cooking, she looks at the pot of water and thinks the water level is much lower than it was. How does this diagram of part of the water cycle help Sharon explain what happened to the pasta water?
Answer:
1. A
2. C
Explanation:
For the first question, we know that the water transformed into a gas. This fact eliminates choices C and D, primarily because they describe the change as "gas to liquid" instead of liquid to gas.
What separates B from A is that B is saying the liquid changed to a gas in response to sunlight, which is completely false and impertinent to the prompt.
A is the correct answer.
for the second question, we know that condensation causes clouds -- and that neither evaporation nor water vapor would clear clouds to make more of them, which eliminates choices B and D. Going back to condensation, the accumulation of water vapor plays a big role in the formation of clouds. While evaporation does play a part in [it] as well, condensation is what caused the sudden appearance of clouds in the troposphere.
C is the correct answer.