Which of the following reactions shows that the formation of CO2 releases
393.5 kJ/mol?
A. C(s) + O2(g) → CO2(g) + 393.5 kJ
O B. C(s) + 20(g) + 393.5 kJ → CO2(9)
O C. C(s) + O(g) + CO2(g) + 393.5 kJ
D. C(s) + O2(g) + 393.5 kJ → CO2(g)
Answers
Answer:
A. C(s) + O2(g) → CO2(g) + 393.5 kJ
Explanation:
The formation of carbon IV oxide (CO2) is an exothermic process. n exothermic process is a chemical process in which heat is evolved. Speaking in lay man's terminology, heat is one of the 'products' of the reaction. This implies that heat is evolved by the process.
The formation of CO2 is always a combustion reaction where heat is evolved or released by the reaction system. Hence the reaction could be shown as;
C(s) + O2(g) → CO2(g) + 393.5 kJ
This implies that 393.5 kJ of energy is released in the reaction in the form of heat. Hence the answer given in the answer box.
Answer: C(s) + O2(g) → CO2(g) + 393.5 kJ
Related Questions
1
Net ionic equations remove spectator ions and shows only the chemical species that are involved in the chemical reaction. Write the net ionic equation for the following acid base reaction.
Molecular Equation: 2 HCl (aq) + Mg(OH)2 (aq) → MgCl2 (aq) + 2 H2O (l)
Complete Ionic: 2 H+ (aq) + 2 Cl– (aq) + Mg2+ (aq) + 2 OH– (aq) → Mg2+ (aq) + 2 Cl– (aq) + 2 H2O (l)
Net Ionic Equation: ______________________________________________________
Answers
Answer:
The reaction of an acid and a base is called a neutralization reaction. ... However, in the reaction between HCl(aq) and Mg(OH) 2(aq), additional molecules of HCl and ... First, we will write the chemical equation with the formulas of the reactants ... The chloride ions are the only spectator ions I THINKS
Explanation:
Calculate the Molarity of a 0.23 mole solution of sucrose, C 12 H 22 O 11 that is dissolved in 5 liters of water.
Answers
Answer:
0.046 M
Explanation:
Molarity = mol solute/ L solution = 0.23 mol/ 5 L = 0.046 mol/L = 0.046 M
what is the difference between an exothermic and endothermic reaction.
Answers
Answer:
An endothermic reaction takes in heat, but feels cold to the touch. An exothermic reaction gives off heat and feels warm to the touch because it is heating the outside objects.
Distillation is a _____________ separation technique.
chemical
physical
Answers
Answer:
Chemical
Explanation:
Because it's being done by chemical means
) What is the definition of an enzyme? A.Enzymes are carbohydrate molecules that act as catalysts to speed up chemical reactions in living things. B.Enzymes are polymer molecules that act as catalysts to slow down chemical reactions in living things. C.Enzymes are protein molecules that act as catalysts to speed up chemical reactions in living things. D.Enzymes are fat molecules that act as catalysts to speed up chemical reactions in living things. E.Enzymes are protein molecules that act as catalysts to slow down chemical reactions in living things.
Answers
Answer:
option c
enzymes are protein molecules that act as catalysts to speed up bio chemical reactions
For neap tides, what must the angular alignment be between the sun, earth and moon?
Answers
Answer:
The angular alignment is 90 degrees
Explanation:
The neap tide is a type of tide which occurs around seven days after a spring tide. This type of tide happens twice every month.
The tide is usually moderate and it exists when the sun and moon are usually at right angles to each other when it occurs. A right angle is also known as 90 degrees which validates the tide occurring at an angle 90.
MY ELEMENT IS SODIUM
1. Summarize the physical and chemical properties of the element you selected.
2. In the lesson, many models were used to depict the atom. How did these models help you understand atomic structure?
3. How do protons, neutrons, and electrons differ in terms of their electrical charges and locations within the atom?
4. Describe the four fundamental forces. Which of these forces are involved in chemical bonding?
Please answer these questions or at least one.
Answers
Answer:
Explanation:
1. The element you selected is Sodium. some of the physical properties are
i. Sodium has a strong metallic lustre
ii. Sodium are usually silver white in color
iii. Sodium is soft it can be cut with knife
iv. Sodium are malleable and ductile.
v. Sodium conduct electricity
Sodium belong to group 1 elements which are called Alkali metals. Sodium have one valency electron and it gives this electron easily during bonding . This is one reason sodium and other alkali metals are very reactive. Sodium can instantly be oxidized by water. Sodium has a relative atomic mass of approximately 23 amu.
2. There are various models that describe atoms .This models includes John Dalton models, J.J Thompson model, Ernest Rutherford model, Bohr's models etc. This models made us understand the role and location of each sub atomic particles. The models shed more light on subatomic particles like electron which revolve around the nucleus. It provide more information on what contribute to the weight of an atom.
3. The proton , neutron and electron are subatomic particles of an atom. The proton and the neutron are located at the nucleus of an atom. The proton and neutron contributes majorly to the weight of an atom. The proton is positively charge while neutron has no charge.
Electron is found to move around the nucleus in cloud. The electron is negatively charge. The electron determines bonding of atoms. An atom is electrically neutral if the number of proton is equal to the number of electron.
4. The four fundamental forces includes weak nuclear forces , strong nuclear forces , gravity and electromagnetic forces.
Weak nuclear forces is responsible for particle decay .Nuclear forces don't play a role in chemical reaction . If they are involve in a reaction it becomes nuclear reaction not chemical reaction.
Strong nuclear forces causes a strong nuclear interaction and it is the strongest among the 4 fundamental forces. This strong force only operate when subatomic particles are much closer to each other.
Gravity force is too weak to affect chemical reaction much. The gravity forces involves the interaction between two objects with energy and mass.
The electromagnetic force act between charged particles like negatively charged electron and positively charged proton. Electromagnetic force is the most important force in chemical bonding as it depends on the arrangement of atoms and the state of their electron. Electromagnetic forces exist in various forms like the covalent bond, metallic, ionic , dipole dipole, hydrogen bonds and many more. The major force involve in chemical bonding is the electromagnetic force.
Which phrase describes a feature of a Mercator projection? is least commonly used sizes most features to scale presents longitude lines as parallel shows most accurately near the prime meridian
QUICK
Answers
Answer:
presents longitude lines as parallel
Explanation:
The Mercator projection shows longitude lines as parallel, hence greatly distorts sizes and distances near the poles. A useful feature is that a course of constant bearing shows as a straight line.
Answer:
C.) presents longitude lines as parallel
Explanation:
Took it on E2020
Name the process that releases carbon dioxide into the atmosphere.
Answers
calculate the ph of a solution containing 0.001 mol dm-3 Naoh
Answers
Answer:
pOH = - log [molarity of OH-] = - log [ molarity of NaOH] , assuming full dissociation. Thus, pOH = - log ( 0.001) = - (-3) = 3. Thus, the pH of 0.001 mol/dm3 NaOH solution is 11.
Explanation:
Hope it'll help!
A.
B.
C.
D.
what’s the correct answer?
Answers
Answer:
C Gamma Rays
Explanation:
Radio waves, on the other hand, have the lowest energies, longest wavelengths, and lowest frequencies of any type of EM radiation. In order from highest to lowest energy, the sections of the EM spectrum are named: *gamma rays* ,X-rays, ultraviolet radiation, visible light, infrared radiation, and radio waves.
Element X is a solid that is brittle, lacks luster,and has six valence electrons. In which group on the Periodic Table would element X be found
Answers
Answer:
Sulfur?
Explanation:
Sulfur has 6 valence electrons and does not have luster.
Which statement accurately describes the movement of Earth’s plates due to convection currents?
Answers
Answer:
Volcanic eruptions.
True Or False? A Load In A Circuit Transforms Light Energy Into Electrical Energy
Answers
Answer:
False
Explanation:
This is because the electrical circuit, where the electrical energy is converted into another form of energy, e.g. lightbulb converts electrical energy into light and heat, an electric bell converts the electrical energy into sound and heat.
False.
The statement a load in a circuit transforms the light energy into electrical energy is False.
What is a load in the circuit?Any device which transforms the electrical energy into other forms of energy, like light energy, sound energy, etc is called an electric load in the circuit.
What is electrical energy?The type of kinetic energy caused by moving electric charges is known as electrical energy. The alternating current, direct current, and batteries provide electrical energy.
So, the load transforms the electrical energy into other forms like light energy, sound energy, etc.
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Give two examples of solutions that you might find or prepare in a kitchen.
Answers
Explanation:
solid liquid
solid gas
liquid solid
3. Sugar solution(sugar + water) is a homogeneous mixture and sugar can be separated from water through evaporation .Comment.
Plz, answer
Answers
Answer:
water is the answer
Explanation:
The sugar and water mix to make sweet water but the sun extracts the sugar from the water leaving only normal water
Answer:
water can be evaporated
Explanation:
the water will be evaporated leaving only the sugar residue behind.
Which represents the greatest time frame in which a short-term environmental change can occur?
in days
O in minutes
O over hundreds of years
O over thousands of years
Answers
Answer:
in days
Explanation:
A short term environmental change refers to changes in the environment that happens within a short period of time, for example, flooding, drought, volcanic eruptions etc. In contrast to short term environmental change, long term environmental change takes place over a long period of time hence species have a longer time to adapt to it. Short term environmental changes may or may not be caused by humans. An example of a short term environmental change caused by humans is oil spillage. Short term environmental changes may lead to the the migration of species from the ecosystem.
Short term environmental changes usually occur within a very short time. The greatest time frame in which a short term environmental change can occur is in a matter of days. Only longterm environmental changes span hundreds and thousands of years.
Answer:
it is c
Explanation:
i took the test :)
which substance will form a solution when mixed with liquid benzene (c6h6)
Answers
Answer: [tex]I_{2} (l)[/tex]
Explanation: Because C 6 H 6 is nonpolar substance and I 2 is also nonpolar compound
According to the concept of solubility,iodine will form a solution when mixed with liquid benzene as both are non-polar substances.
What is solubility?Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
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scientists often work on projects for a long time and fail to see sources of error in their research. Which process allows an outside expert to look at the scientist’s project and point to sources of error?
Answers
Answer:
Replication
Explanation:
In science, the work of a scientist is regarded as authentic if other experts in other places can follow the same steps as he/she claimed to follow and arrive at the same result.
For example, a scientist in California, United States of America may carry out a research and publish his findings. Another scientist in Christchurch New Zealand following exactly the same procedure is expected to arrive at the same results as the original researcher if there were no errors in the work.
However, where there are disparities in results, the scientist in Newzealand may discover errors that were unknown to the original researcher in the united States. The New Zealand scientist was carrying out a process known as 'replication'. That is, repeating a scientific research in order to obtain the same results thereby validating the research.
What is the molarity of a solution prepared by dissolving 7.0 moles of NaCl solute in 585 ml of solution
?
Answers
Answer:
12 mol/L
Explanation:
Molarity = moles/L solution = 7.0 mol /0.585 L ≈ 12 mol/L
15. Calculate the hydrogen ion concentration of a
solution whose pH is 2.4
A 3.6 x 0.01
B 2.5 x 0.0001
C 2.5 x 0.01
D 7.0 x 0.01
Answers
Answer:
Explanation:
pH = − log [H+] , we can solve for [H+] as,
− pH = log [H+] ,
[H+] = 10^−pH,
so PH =2.4 in you case is
[H+] = 10^-2.4 =0.00398
The option are not correct it looks
What shape would a molecule with two bound groups and two lone pairs
have?
A. Trigonal pyramidal
B. Tetrahedral
C. Linear
D. Bent
Answers
Answer:
It would have to be D, a bent shape
Explanation:
I just took the quiz
Which of the following statements is true? Less rain and snow falls in smoky areas than in other areas. Acid rain causes corrision of buildings and statues. The first laws againts pollution were passed in the 1990s. Cars are the leading cause of nitrogen oxide pollution.
Answers
Answer:
Acid rain causes corrosion in buildings.
Explanation:
This is true because acid rain over time can eat away at the building.
Predict your observation if a magnesium ribbon is put in potassium hydroxide solution and tested with a lighted wooden splinter.
Answers
mg reacts with the acid and produce visible bubbles of hydrogen gas. they will produce audible pops as the hydrogen ignites. ... Hydrochloric acid is a corrosive liquid. Hydrogen gas is explosive.
An acid is added to water, and a new equilibrium is established. What is the system after the acid is added? A. pH w = 1 x 10-14 B. pH w -14 C. pH > pOH and Kw = 1 x 10-14 D. pH > pOH and Kw > 1 x 10-14
Answers
Answer:
C. pH > pOH; Kw = 1.0 * 10^-14
Explanation:
The ion product of water, Kw = [H+]*[OH-] = 1.0 * 10^-14. It is a constant.
When an acid or base is added to water, its ion product does not change as it a constant. However, the relative concentrations of H+ ions and OH- ions will change depending on whether an acid or base is added to water.
When an acid is added to water, the concentration of H+ ions increases while that of OH- ions decreases, and vice versa.
Therefore, in the above situation where an acid is added to water, pH > pOH; Kw = 1.0 * 10^-14
What are the two ways that humans lose heat? PLS help thank you!
Answers
Answer:
Evaporation, Radiation
Explanation:
Evaporation of water from your skin if it is wet (sweating). ...
Radiation (similar to heat leaving a woodstove).
Step 3: Measure Solubility in Cold Water
10
0
-10
80
100 m
60
-40
20
Temperature of the water to the nearest degree:
ANSWER IS 2°C. !!!
Answers
Answer:
2 degrees celcius
Explanation:
The density was of a solution of sulfuric acid is 1.285g/cm3 and it is 38.08% (by weight) acid. How many millimeters of the acid solution do you need to supply 125 grams of sulfuric acid?
Answers
Answer:
255.5cm³
Explanation:
A solution that is 38.08 % by weight has 38.08g of sulfuric acid per 100g of total solution. Thus, mass of solution you need to obtain 125g is:
125g H₂SO₄ × (100g solution / 38.08g H₂SO₄) = 328.3g of solution
As density of the solution is 1.285g / cm³, the volume of 328.3g is:
328.3g × (1cm³ / 1.285g) = 255.5cm³
WILL MARK BRAINLIEST IF GOOD EXPLANATION...
Ethyl acetate is a sweet-smelling solvent used in varnishes and fingernail polish remover. It is produced industrially by heating acetic acid and ethanol
together in the presence of sulfuric acid, which is added to speed up the
reaction. The ethyl acetate is distilled off as it is formed. The equation for the
process is as follows.
CH3COOH + CH3CH2OH --> CH3COOCH2CH3 + H2O
Determine the percentage yield in the following cases:
a. 68.3 g of ethyl acetate should be produced but only 43.9 g is recovered.
b. 0.0419 mol of ethyl acetate is produced but 0.0722 mol is expected. (Hint:
Percentage yield can also be calculated by dividing the actual yield in moles
by the theoretical yield in moles.)
c. 4.29 mol of ethanol is reacted with excess acetic acid, but only 2.98 mol of
ethyl acetate is produced.
d. A mixture of 0.58 mol ethanol and 0.82 mol acetic acid is reacted and 0.46
mol ethyl acetate is produced. (Hint: What is the limiting reactant?)
Answers
Answer:
a) 64.27%
b) 58%
c) ethanol is the limiting reactant
d) ethanol is the limiting reactant
Explanation:
We have to note that the expected yield is the theoretical yield while the actual mass or amount of product formed is the actual yield.
a) theoretical yield=68.3g
Actual yield= 43.9 g
Percentage yield= 43.9/68.3 ×100
Percentage yield= 64.27%
b) theoretical yield= 0.0722 moles
Actual yield = 0.0419
Percentage yield= 0.0419/0.0722 × 100
Percentage yield= 58%
c) note that the limiting reactant yields the least number of moles of product
Ethanol will be the limiting reactant since it is not present in excess.
d) from the reaction equation;
1 mole of acetic acid produces 1 mole of ethyl acetate
0.58 moles of ethanol produces 0.58 moles of ethyl acetate
1 mole of acetic acid yields 1 mole of ethyl acetate
Hence 0.82 moles of acetic acid yields 0.82 moles of ethyl acetate
Hence ethanol is the limiting reactant.
What is the molarity of a solution that contains 2 moles of KCl in 4 L of solution? a 2.0 M b 0.5 M c 0.25 M d 8.0 M
Answers
Answer:
A.) 2.0 M
Explanation:
Molarity=mole of solutes/Liters of solution so M=mol/L
2moles/4 L =2 M