Answer:
-177.9 kJ.
Explanation:
Use Hess's law. Ca(s) + CO2(g) + 1/2O2(g) → CaCO3(s) ΔH = -812.8 kJ 2Ca(s) + O2(g) → 2CaO(s) ΔH = -1269.8 kJ We need to get rid of the Ca and O2 in the equations, so we need to change the equations so that they're on both sides so they "cancel" out, similar to a system of equations. I changed the second equation. Ca(s) + CO2(g) + 1/2O2(g) → CaCO3(s) ΔH = -812.8 kJ 2CaO(s) → 2Ca(s) + O2(g) ΔH = +1269.8 kJ The sign changes in the second equation above since the reaction changed direction. Next, we need to multiply the first equation by two in order to get the coefficients of the Ca and O2 to match those in the second equation. We also multiply the enthalpy of the first equation by 2. 2Ca(s) + 2CO2(g) + O2(g) → 2CaCO3(s) ΔH = -1625.6 kJ 2CaO(s) → 2Ca(s) + O2(g) ΔH = +1269.8 kJ Now we add the two equations. The O2 and 2Ca "cancel" since they're on opposite sides of the arrow. Think of it more mathematically. We add the two enthalpies and get 2CaO(s) + 2CO2(g) → 2CaCO3(s) and ΔH = -355.8 kJ. Finally divide by two to get the given equation: CaO(s) + CO2(g) → CaCO3(s) and ΔH = -177.9 kJ.
When the medium is uniform, how do light waves travel through it?
a. vibrating motion
b. circular motion
c. irregular motion
d. straight line motion
Answer:
d.straight line motion
Answer:
d.) straight line motion
Explanation:
i just took the k12 test
A force caused by objects moving in opposite directions called
Answer: Balanced forces
Explanation: Equal forces acting in opposite directions are called balanced forces. Balanced forces acting on an object will not change the object's motion.
PLS HELP MARKING BRAINLIEST! (Dont answer if u dont know and please don't answer random things-)
What happens when Mentos and Diet Coke are mixed?
What causes Mentos and Diet Coke to react that way?
Is the reaction Chemical or Physical?
How could we prove one way or the other?
When mentos and diet coke are mixed, the diet soda explodes
Explanation:
Due to the fact that the mentos are dense, they sink to the bottom of the bottle which gives the diet coke its explosion.
Answers & Explanations:
What happens when Mentos and Diet Coke are mixed?
Mentos sinks rapidly through the liquid, causing a fast, large eruption.
What causes Mentos and Diet Coke to react that way?
The addition of the Mentos leads to the rapid nucleation of carbon dioxide gas bubbles in the Diet Coke, causing them to precipitate out of the solution.
Is the reaction Chemical or Physical?
The eruption is caused by a physical reaction.
How could we prove one way or the other?
We can prove it by using the equation:
[tex]CO_{2} (aq) = Co_{2}(g)[/tex]
If there are 27 grams of nitrogen dioxide at STP how many liters does this occupy?
Answer:
30 liters
Explanation:
Compute the percentage of error to the nearest tenth in the student’s calculation if the actual specific heat value for aluminum is 0.9J:g*C.
Complete Question:
1. A block of aluminum with a mass of 140 g is cooled from 98.4°C to 62.2°C with a release of 4817 J of heat. From these data, calculate the specific heat of aluminum.
a. Compute the percentage of error to the nearest tenth in the student's calculation if the actual specific heat value for aluminum is 0.9 J/g°C
Answer:
Percent error = 55.56 %
Explanation:
Given the following data;
Mass = 140 grams
Initial temperature = 62.2°C
Final temperature = 98.4°C
Quantity of heat = 4817 Joules.
To find the specific heat capacity;
Heat capacity is given by the formula;
[tex] Q = mcdt[/tex]
Where;
Q represents the heat capacity or quantity of heat. m represents the mass of an object. c represents the specific heat capacity of water. dt represents the change in temperature.dt = T2- T1
dt = 98.4 - 62.2
dt = 36.2°C
Making c the subject of formula, we have;
[tex] c = \frac {Q}{mdt} [/tex]
Substituting into the equation, we have;
[tex] c = \frac {4817}{140*36.2} [/tex]
[tex] c = \frac {4817}{5068} [/tex]
Specific heat capacity, = 0.95 J/g°C
b. To find the percentage error;
Given the following data;
Actual specific heat capacity = 0.9 J/g°C
Experimental specific heat capacity = 0.95 J/g°C
Percent error can be defined as a measure of the extent to which an experimental value differs from the theoretical value.
Mathematically, it is given by this expression;
[tex] Percent \; error = \frac {experimental \;value - actual \; value}{ actual \;value} *100[/tex]
Substituting into the formula, we have;
[tex] Percent \; error = \frac {0.95 - 0.9 }{ 0.9} *100[/tex]
[tex] Percent \; error = \frac {0.5}{0.9} *100[/tex]
[tex] Percent \; error = 0.5556 *100[/tex]
Percent error = 55.56 %
List the elements and the amounts of each element below for 5 Li2S04.
Answer:
Lithium has 5 elements, sulphur has 2 elements and oxygen has 4 elements
At another temperature, the rate constant is 3.25 M-2 s-1. What is the rate at this temperature for the
given concentrations?
Answer:
It's 0.00015
Explanation:
got it right on edge 2021
How can a weaker party impact the law making process?
Answer: This is due to a dominance of political parties over ... legislative process, the influence opposition has on amending the government bills and formal and effective
Explanation: hope u get it right
when was the element copper discovered? Who discovered the element copper?
The Mesopotamians discovered copper (Cu) in 9000 BC.
HELP 15-21 PLEASE ASAP!!
Answer:
15-21 is 6
Explanation:
a diagram of the electromagnetic spectrum is shown. which wavelength is the longest safest wavelengths for humans？ Helppp pleaseee
Answer:
radio waves
Explanation:
the answer is simple, radio waves. it is radio waves because when you look at the diagram the waves below Radio are very long. if you look at the waves under gamma ray, they are very short. radio is the longest wave while gamma is the shortest. if you are still confused it also says longer wavelength and low frequency( meaning it is safe) right under the wavelength.
Question 2
1 pts
Which of the following best describes what families/groups of elements have in common?
O Same number of electrons
O Same number of valence electrons
O Same number of electron shells
O Same number of protons
U
Question 3
1 pts
A buoy bobs up and down in the ocean. The waves have a wavelength of
2.5 m, and they pass the buoy at a speed of 4.0 m/s. What is the frequency
of the waves?
A. 1.6 Hz
B. 10 Hz
C. 6.5 Hz
D. 1.5 Hz
Answer:
c
Explanation:
Explain Newton's 2nd Law of motion
Answer:
Newtons second law says that acceleration (gaining speed) happens when a force acts on a mass (object)
Explanation:
For example riding your bicycle, your bicycle is the mass and your leg muscles pushing on the pedals of your bicycle is the force.
what are the advantages of using Fahrenheit ?
Answer:
You can better relate to the air temperature.
Explanation:
Fahrenheit gives you almost double the precision of Celsius without having to use decimals.
Which would be the best starting question to determine
the composition of the Outer Core and the Inner Core?
A) Are the Outer Core and the Inner Core composed of
large amounts of iron?
B) How much rock do the Outer Core and the Inner Core
contain?
C) How deep in the Earth are the Outer Core and the
Inner Core?
D) Are the Outer Core and the Inner Core composed of
large amounts of metal?
For the following equation insert the correct coefficients that would balance the equation. If no coefficient is need please insert the NUMBER 1.
1. CH4 + O2 --> CO2 + H2O
Answer:
1CH₄ + 2O₂ -> 1CO₂ + 2H₂O
Explanation:
Reactants:
1 C
4 H
4 O
Products:
1 C
4 H
4 O
The equation is balanced.
Given the balanced chemical equation: 2 H2 + O2 → 2 H20. Choose
the description below that most accurately describes the reaction.
O 2 moles of hydrogen react with 1 mole of oxygen to form 2 moles of water
O 2 moles of water react with 1 mole of hydrogen to form 2 moles of oxygen
O equal moles of hydrogen and oxygen react to form an equal amount of
water
O 4 moles of hydrogen react with 2 moles of oxygen to form 4 moles of water
Answer:
The answer is
2 moles of hydrogen react with 1 mole of oxygen to form 2 moles of water
What is the percent by volume of a solution that has 45 mL of ethanol CH3OH dissolved in 255 mL of water?
Answer:
Percent volume-volume (%(v/v)) = 100 x (volume of solute / volume of solution)
Percent volume-volume (%(v/v)) = 100 x (volume of solute / volume of solution)ex. 20 ml of methanol dissolved in enough water to make 200 ml of solution would result in a 10 % methanol solution
Percent volume-volume (%(v/v)) = 100 x (volume of solute / volume of solution)ex. 20 ml of methanol dissolved in enough water to make 200 ml of solution would result in a 10 % methanol solution-the units may be any units of volume you chose - as long as they are consistent
Percent volume-volume (%(v/v)) = 100 x (volume of solute / volume of solution)ex. 20 ml of methanol dissolved in enough water to make 200 ml of solution would result in a 10 % methanol solution-the units may be any units of volume you chose - as long as they are consistent-this concentration unit is most often used when mixing two liquids
C.
Calculate the number of moles in 62g of CO2
Answer:
32÷5
I'm just tryna get points I'm sorry
goodluck tho❤
What volume of 0.062 M HCl is needed to react to completely neutralize 19.4 mL of 0.050 M Ba(OH)2? *
Answer:
31.3 mL
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2HCl + Ba(OH)₂ —> BaCl₂ + 2H₂O
From the balanced equation above,
The mole ratio of the acid, HCl (nₐ) = 2
The mole ratio of the base, Ba(OH)₂ (n₆) = 1
Finally, we shall determine the volume of the acid need for the reaction as follow:
Molarity of acid, HCl (Mₐ) = 0.062 M
Mole ratio of the acid, HCl (nₐ) = 2
Volume of base, Ba(OH)₂ (V₆) = 19.4 mL
Molarity of base, Ba(OH)₂ (M₆) = 0.050 M
Mole ratio of the base, Ba(OH)₂ (n₆) = 1
Volume of acid, HCl (Vₐ) =?
MₐVₐ / M₆V₆ = nₐ / n₆
0.062 × Vₐ / 0.050 × 19.4 = 2/1
0.062 × Vₐ / 0.97 = 2
Cross multiply
0.062 × Vₐ = 0.97 × 2
0.062 × Vₐ = 1.94
Divide both side by 0.062
Vₐ = 1.94 / 0.062
Vₐ = 31.3 mL
Thus, the volume of the acid needed is 31.3 mL
Which of the following statements is true?
Volcanoes can form mountains and islands.
Most changes to the crust happen slowly over time.
Plateaus are large, flat areas of land more than two thousand feet tall.
all of the above
Is combining ammonium chloride and water a physical or chemical change
convert 2.41 x 10^2 m to cm
answer choices
2.41cm
2.41 x 10^4cm
2.41 x 10^-2cm
2.41 x 10^-6cm
Answer:
2.41*10² m equals 2.41*10⁴ cm
Explanation:
The rule of three or is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them. That is, what is intended with it is to find the fourth term of a proportion knowing the other three. Remember that proportionality is a constant relationship or ratio between different magnitudes.
If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other (or when one magnitude decreases, so does the other) , the direct rule of three must be applied. To solve a direct rule of three, the following formula must be followed:
a ⇒ b
c ⇒ x
So: [tex]x=\frac{c*b}{a}[/tex]
In this case the rule of three can be applied as follows: if 1 m equals 100 cm, 2.41*10² m equals how many cm?
[tex]cm=\frac{2.41*10^{2} m*100 cm}{1 m}[/tex]
cm= 24100 = 2.41*10⁴
2.41*10² m equals 2.41*10⁴ cm
How many molecules are there in 24 grams of HSO₃?
What is the potential energy of a rollercoaster if it weighs 1565 kg and sits on a 115 m tall ride?
Answer:
Explanation:
Potential energy builds as the coaster is going up the loop-the-loop and converts to kinetic energy on the way down and out of the loop-the-loop. The potential energy of the coaster is at its lowest and the kinetic energy is at its highest as the coaster moves in the lowest point of the loop-the- loop.
A student dilutes 50.0 mL of a 0.10 mol/L to 0.010 mol/L. Which statement is true?
Which indicator would show a pH change from 6 to 7?
A. Red litmus indicator
B. Methyl red indicator
C. Phenol red indicator
D. Blue litmus indicator
Answer:
c
Explanation:
1. litmus paper is used when showing a change between a greater range in ph levels - so A and D are automatically a no.
2. methyl red is used to show a range in ph levels between 4.8-6
3. Option C is the only one left so im going to assume its C because its definitely not A, B, or D
Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the free energy change for the process is positive or negative and explain your answer.
The given question is incomplete. The complete question is:
Consider the spontaneous dissolution of NaCl in water: NaCl(s) → Na+(aq) + Cl −(aq) Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the free energy change for the process is positive or negative and explain your answer.
Answer: The entropy change is positive. The free energy change for the process is negative and reaction is spontaneous.
Explanation:
Entropy is defined as the degree of randomness of a system. For a system in which randomness increses , the enetropy is said to increase and [tex]\Delta S[/tex] is positive.
As in the given reaction : [tex]NaCl(s)\rightarrow Na^+(aq)+Cl^-(aq)[/tex] , the solid is dissociating to give ions , randomness increases and thus entropy is positive.
Also the dissociation of a molecule requires energy , thus the enthalpy [tex]\Delta H[/tex] is also positive as heat is absorbed by the system.
[tex]\Delta G=\Delta H-T\Delta S[/tex]
[tex]\Delta G=(+ve)-T(+ve)[/tex]
[tex]\Delta G=-ve[/tex] when Temperature is high.
Consider the spontaneous dissolution of NaCl in water: NaCl(s) → Na+(aq) + Cl −(aq)
Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the free energy change for the process is positive or negative and explain your answer.
The given question is incomplete. The complete question is:
Consider the spontaneous dissolution of NaCl in water: NaCl(s) → Na(aq) Cl −(aq) Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the free energy change for the process is positive or negative and explain your answer.
Answer: The entropy change is positive. The free energy change for the process is negative and reaction is spontaneous.
Explanation:
Entropy is defined as the degree of randomness of a system. For a system in which randomness increses , the enetropy is said to increase and is positive.
As in the given reaction : , the solid is dissociating to give ions , randomness increases and thus entropy is positive.
Also the dissociation of a molecule requires energy , thus the enthalpy is also positive as heat is absorbed by the system.
when Temperature is high.
Which of these ideas did you include in your answer?
✔️ When a crystalline solid dissolves, it becomes more disordered.✔️ When disorder increases, ΔG is positive.✔️ This process probably has a positive ΔS .✔️ The process is spontaneous.✔️ Spontaneous processes have ΔG < 0; the process has a negative ΔG .
Have a Nice Day .
is it unsaturated, saturated, or super saturated
Answer:
saturated
Explanation:
It is not dense enough to be supersaturated.
Answer:
unsaturated
Explanation:
salts arent fatty