When the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation is halved and has its sign changed.
Let's consider the following intermediate chemical reactions.
Reaction 1: Ca(s) + CO₂(g) + ½O₂(g) → CaCO₃(s) ΔH₁ = -812.8 kJ
Reaction 2: 2 Ca(s) + O₂(g) → 2 CaO(s) ΔH₂ = -1269 kJ
We want to calculate the enthalpy of the following overall chemical equation.
CaO(s) + CO₂(g) → CaCO₃(s) ΔH = ?
We can apply Hess' law.
What is Hess' law?Hess' law states that regardless of the multiple stages or steps of a reaction, the total enthalpy change for the reaction is the sum of all changes.
To apply Hess' law in this case we have to:
Conserve equation 1 as is.Reverse equation 2 and multiply it by 1/2, thus changing the sign of its enthalpy and multiplying it by 1/2.Add both equations and their enthalpies.Ca(s) + CO₂(g) + ½ O₂(g) → CaCO₃(s) ΔH = -812.8 kJ
+
CaO(s) → Ca(s) + ½ O₂(g) ΔH = 634.5 kJ
--------------------------------------------------------------------------------------
CaO(s) + CO₂(g) → CaCO₃(s) ΔH = -178.3 kJ
When the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation is halved and has its sign changed.
The complete question is as follows.
Consider the intermediate chemical reactions.
Ca (s) + CO₂ (g) + ½O₂ (g) → CaCO₃ (s) ΔH₁ = -812.8 kJ
2Ca (s) + O₂ (g) → 2CaO (s) ΔH₂ = -1269 kJ
The final overall chemical equation is
CaO (s) + CO₂ (g) → CaCO₃ (s) ΔH = ?
When the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation
is halved and has its sign changed. is halved. has its sign changed. is unchanged.Learn more about Hess' law here: https://brainly.com/question/11628413
Answer:
Consider the following intermediate reactions.
CH₄(g)+2O₂(g)⇒CO₂(g)+2H₂O(g) ΔH₁ = -802 kJ
2H₂O(g)⇒2H₂O(I) ΔH₁ = - 88 kJ
The overall chemical reaction is as follows.
CH₄(g)+2O₂(g)⇒CO₂(g)+2H₂O(I) ΔH₂ = -890 kJ
What is the correct enthalpy diagram using the Hess law for this system?
✔️ A←❌ B
❌ C
❌ D
what happens when light is not spread out
Answer:
Spreading out a wave over a larger area just causes the wave strength to weaken, but does not cause gaps to form. Therefore, if you look at photons as waves, spatial gaps never form in light as it travels through free space, no matter how dim it gets.Spreading out a wave over a larger area just causes the wave strength to weaken, but does not cause gaps to form. Therefore, if you look at photons as waves, spatial gaps never form in light as it travels through free space, no matter how dim it gets
Explanation:
In order to control pollution, you should reduce the need for _____________ goods and transportation.
Answer:manufacture
Explanation:
The pollution can be controlled with the help of reducing the need for the manufactured good and transportation.
What is pollution?A pollution can be given as the presence of the harmful substances in the environment. The harmful substances known as pollutants deteriorate the quality of the environment and effect the health of living organism as well.
The pollution in air has been contributed with the increased need of the manufactured goods and transportation, and thereby the reduction will be found to reduce the pollution too.
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What does the questions “how much?” and “how many?” have in common?
3z-1
= 162+2.642-2
4
Z=
the answer is z = 47.214
Answer:
z = 47.214
Hope this helped
The pressure of a 70.0L sample of gas is 600 mm Hg at 20.0C. If the temperature drops to 15.0C and the volume expands to 90.0L, what will the pressure of the gas be?
Answer:
458.7 mmHg
Explanation:
Step 1:
Data obtained from the question. This includes:
Initial volume (V1) = 70L
Initial pressure (P1) = 600 mmHg
Initial temperature (T1) = 20°C
Final temperature (T2) = 15°C
Final volume (V2) = 90L
Final pressure (P2) =...?
Step 2:
Conversion of celsius temperature to Kelvin temperature.
This is illustrated below:
T(K) = T (°C) + 273
Initial temperature (T1) = 20°C
Initial temperature (T1) = 20°C + 273 = 293K
Final temperature (T2) = 15°C
Final temperature (T2) = 15°C + 273 = 288K
Step 3:
Determination of the new pressure of the gas.
The new pressure of the gas can be obtained by using the general gas equation as shown below:
P1V1/T1 = P2V2/T2
600 x 70/293 = P2 x 90/288
Cross multiply to express in linear form
P2 x 90 x 293 = 600 x 70 x 288
Divide both side by 90 x 293
P2 = (600 x 70 x 288) / (90 x 293)
P2 = 458.7 mmHg
Therefore, the new pressure of the gas is 458.7 mmHg
HELPPP. What is the molarity (molar concentration) of a 500.0mL that contains 5.60g of KOH? Please show your work, with units, and include a therefore statement.
Answer:
.2 M
Explanation:
grams/molar mass=ans./volume(L)=molarity
5.6/56=ans./.500=.2 M
- Hope that helps! Please let me know if you need further explanation.
Analysis: The limiting reactant(s) appeared to be
because
there is nothing with which it can react
Explanation:
The limiting reactant(s) prevents a reaction from continuing because there is none left.
Why do limiting reactants occur?Identification of the limiting reactant makes it possible to calculate the theoretical yield of a reaction. The reason there is a limiting reactant is that elements and compounds react according to the mole ratio between them in a balanced chemical equation.
How do you get the limiting reactant?The reactant that is consumed first and limits the amount of product(s) that can be obtained is the limiting reactant. To identify the limiting reactant, calculate the number of moles of each reactant present and compare this ratio to the mole ratio of the reactants in the balanced chemical equation.
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Which is the molar mass of Calcium?
Answer:
40.078 u
Explanation:
Which of the following did Antoine Lavoisier correctly characterize as an element? light silicone dioxide mercury
Answer: mercury
Explanation: I looked up the answer to your question.
Answer:
Mercury
Explanation:
I did this question and I got it right.
ILL GIVE YOU BRAINLIST * have to get it right * !!! Although individual body systems can perform specific functions, they depend on one another and work together for the good of the entire organism.
Which of the following provides the best evidence that the digestive system and the muscular system work together to carry out their functions?
What are three examples of acid-base reactions in cooking
Answer:
Lemon juice baking soda and vinegar
Explanation:
1. Calculate the molarity of 35g of calcium chloride (CaCl2) that is dissolved in 850ml of water. (Calculate moles first)
a. 0.27M
b. 0.38M
c. 0.32M
d. 0.80M
2. Calculate the molarity of 90g of copper sulfate (CuSO4) when dissolved in 5 L of water.
a. 0.112M
b. 2.8M
c. 0.56M
d. 0.50M
3. What is the molarity of NaOH if 0.70 moles are dissolved in 250 ml of water?
a. 175,000M
b. 2.8M
c. 0.175M
d. 4M
4. How many moles of Lithium oxide (Li20) are in 2 L of solution with a molarity of 2.0M?
a. 1 mole
b. 2 moles
c. 0.2 moles
d. 4 moles
5. How many moles of NaCl are in 7.5 L of 0.5M?
a. 3.75 moles
b. 15 moles
c. 0.066 moles
d. 2.5 moles
Answer:
yo I got same question do u know it
Which of the following is an example of the endocrine system maintaining homeostasis?
Group of answer choices
Detecting a pain stimulus and sending a signal to the spinal cord to perform an automatic response
Producing an excessive amount of hormones in the blood and not sending a signal to stop production
Releasing insulin to decrease blood sugar and releasing glucagon to increase blood sugar
Using sense organs to get information about the outside world and direct an appropriate body response
Answer:Releasing insulin to decrease blood sugar and releasing glucagon to increase blood sugar
Explanation: homoestasis is the process by which the body keep it's internal environment constant, regardless of change in the external environment. The human body has a normal range in which it's system operates and it uses homoestasis to keep these at constant.
Homeostasis could be positive or negative. It usually involves a sensor which detects the changes in the body and passes the information to the control center, a control center which receive information from the sensor and sends signals to the effectors and the effector which acts on the information sent by the control center to effect normalcy.
In this case, when a person eats food,he gets glucose. Blood sugar most be kept at constant so the endocrine system release the hormone insulin. Insulin helps to convert glucose to glycogen, which is the form it can be stored in the liver
When the blood sugar levels is low, the brain which is the control center causes glucagon to be released . This hormone converts glycogen to glucose
Answer:
Answer:Releasing insulin to decrease blood sugar and releasing glucagon to increase blood sugar
Explanation:
Why does the addition of a solute lower the freezing point of a solution?
A The solute is colder than the solvent.
B The solute disrupts crystal formation by the solvent.
C The solute tends to sink to the bottom of the solution.
D The solute has bigger molecules than the solvent.
Answer:
B
Explanation:
Calculate the molarity of a nitric acid solution if 38 ml of the solution is neutralized by 16 ml of 0.25 M barium hydroxide solution. The balanced equation for the reaction is
Answer:
l
Explanation:
What is the value for AG at 500 Kif AH = 27 kJ/mol and AS = 0.09 kJ/(mol-K)?
Answer: -18
Explanation:
Facts
What is the value for ΔG at 500 K if ΔH= 27 kJ/mol and ΔS = 0.09 kJ/(mol⋅K)?
Explanation: ΔG= -18 kJ/mol
does temperature and pressure affect the solubilty of any solute
Answer:
Yes very much so, especially gases
Explanation:
Solubility of gases decrease with increasing pressure. Be familiar with Henry's Law.
- Hope that helps! Please let me know if you need further explanation.
Answer:
Yes, it does.
A radioactive isotope has a half life of 25 minutes. How many half lives have occurred after 175 minutes?
5
6
7
8
Will give Brainliest
Answer:
7
Explanation:
Complete and balance this neutralization reaction: HNO3 + Al(OH)3
Answer:
Al(OH)3 + HNO3 = Al(NO3)3 + H2O - Chemical Equation Balancer.
Explanation:
how many number of electrons are in aluminium and nitrogen in their free state?
Answer:
MRCORRECT has answered the question
Explanation:
13 electrons
So... for the element of ALUMINUM, you already know that the atomic number tells you the number of electrons. That means there are 13 electrons in a aluminum atom. you can see there are two electrons in shell one, eight in shell two, and three in shell three.
7 electrons
So... for the element of NITROGEN, you already know that the atomic number tells you the number of electrons. That means there are 7 electrons in a nitrogen atom. Looking at the picture, you can see there are two electrons in shell one and five in shell two.
The Sun is a constant supply of energy to Earth.
A. True
B. False
Which of these conclusions is correct about P and Q in the diagram?
P represents the land and Q represents the ocean.
P represents the ocean and Q represents the land.
P represents the land and Q represents the atmosphere.
P represents the atmosphere and Q represents the ocean.
Answer:
P represents the atmosphere and Q represents the ocean.
Explanation:
How many times more acidic is a pH of 2 than a PH of 7?
Answer: 10 times more
Explanation:
How many senses does the human body have?
O A. 3
B. 5
Answer:
B
Explanation:
sight, hearing, smell, taste and touch
Answer:
Most easiest answer..
There are 5 senses in human body.☺️
Calculate the molar mass of ammonium chloride
Answer:
53.491 g/mol
Explanation:
Create the chemical compound and find each individual element's molar mass. Lastly, add them up.
You are given the reaction Cu + HNO3 Cu(NO3)2 + NO + H2O complete the final balanced equation based on half-reactions
The balanced equation based on half-reactions is 2Cu + 8HNO3 + 6H+ -> 2Cu(NO3)2 + 2NO + 4H2O.
How to determine the balanced equation based on half-reactionsTo complete the balanced equation for the given reaction Cu + HNO3 -> Cu(NO3)2 + NO + H2O using half-reactions, we need to break down the overall reaction into separate oxidation and reduction half-reactions.
1. Oxidation Half-Reaction:
Cu -> Cu2+ + 2e-
In this step, copper (Cu) is oxidized, losing two electrons to form copper(II) ions (Cu2+).
2. Reduction Half-Reaction:
HNO3 + 3H+ + 2e- -> NO + 2H2O
In this step, nitric acid (HNO3) is reduced, gaining two electrons to form nitric oxide (NO) and water (H2O).
Now, to balance the half-reactions, we need to make sure that the number of electrons gained in the reduction half-reaction is equal to the number of electrons lost in the oxidation half-reaction. In this case, we can achieve this by multiplying the oxidation half-reaction by two.
Balanced Half-Reactions:
Oxidation: 2Cu -> 2Cu2+ + 4e-
Reduction: HNO3 + 3H+ + 2e- -> NO + 2H2O
Finally, we can combine the balanced half-reactions to obtain the balanced equation for the overall reaction:
2Cu + 8HNO3 + 6H+ -> 2Cu(NO3)2 + 2NO + 4H2O
Therefore, the balanced equation based on half-reactions is 2Cu + 8HNO3 + 6H+ -> 2Cu(NO3)2 + 2NO + 4H2O.
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Write the full symbol for the isotope of oxygen having 8 neutrons.
Answer:
Isotopes are forms of a chemical element that have the same atomic number but differ in mass. 16O → 8 protons + 8 neutrons; a “light” oxygen); The relative amounts are expressed as either 18O/16O or δ 18O Oxygen - 18 (aka 18O → 8 protons + 10 neutrons; a “heavy” oxygen).
A 0.050L solution of Ba(OH)2 is neutralized by 0.072L of a 0.55 M HNO3 solution. What is the concentration of the Ba(OH)2 solution?
Answer:
0.396M
Explanation:
Step 1:
The balanced equation for the reaction. This is given below:
2HNO3 + Ba(OH)2 —> Ba(NO3)2 + 2H2O
From the balanced equation above,
The mole ratio of the acid (nA) = 2
The mole ratio of the base (nB) = 1
Step 2:
Data obtained from the question. This include the following:
Volume of base (Vb) = 0.05L
Concentration of base (Cb) =..?
Volume of acid (Va) = 0.072L
Concentration of acid = 0.55 M
Step 3:
Determination of the concentration of the base, Ba(OH)2.
The concentration of the base, Ba(OH)2 can be obtained as follow:
Cava /CbVb = nA/nB
0.55 x 0.072 / Cb x 0.05 = 2/1
Cross multiply to express in linear form
Cb x 0.05 x 2 = 0.55 x 0.072
Divide both side by 0.05 x 2
Cb = (0.55 x 0.072) / (0.05 x 2)
Cb = 0.396M
Therefore, the concentration of the base, Ba(OH)2 is 0.396M
The element hydrogen has the highest specific heat of all elements. At room temperature, hydrogen's specific heat is 14.30 J/g •°C. If the temperature of a 340.0 g sample of hydrogen is to be raised by 30°C, how much energy will have to be added to the hydrogen?
Answer:
THE ENERGY NEEDED TO BE ADDED TO RAISE THE TEMPERATURE BY 30°C IS 145, 860 J
Explanation:
The energy needed can be calculated by using the heat formula, which is;
Heat = m c ΔT
m = mass of the hydrogen = 340 g
c = specific heat capacity of hydrogen at room temperature = 14.30 J/g°C
ΔT = change in temperature = 30°C
Heat =?
So therefore,
Heat = 340 * 14.30 * 30
Heat = 145860 J
The energy needed to be added to the hydrogen to bring the mass of 340 g to an increased temperature of 30°C is 145, 860 J or 145.86kJ
Grinding a seltzer tablet into powder increases the rate of reaction due to an increase of which factor?
Temperature
Surface area
Reactants
Concentration
Answer:
Surface area
Explanation:
The rate of a chemical reaction is increased when the surface area of a solid reactant is increased. This can be done by cutting the substance into small pieces, or by grinding it into a powder. If the surface area of a reactant is increased, it implies more particles are exposed to the other reactant.
When a seltzer tablet is ground into powder, the idea is to expose more of its surface to the other reactant. Since rate reaction depends on effective collision between reactants, more exposed particles implies a greater degree of collision between reactants and a faster rate of reaction.
Answer:
the answer is the second option got it right so do worry
Explanation:
hope this helps
