Answer:
Explanation:
When animals breathe or decompose (decay), carbonate rocks weather, forest fires ignite, and volcanoes erupt, carbon dioxide is released into the atmosphere naturally. Human practices such as the combustion of fossil fuels and trees, as well as the manufacture of cement, contribute carbon dioxide to the atmosphere.
One method for determining the identity of an unknown organic compound is through combustion analysis. A sample of an unknown substance is burned, and the amounts of water and carbon dioxide produced can be used to find the relative amounts of carbon, hydrogen, and oxygen. These devices can be modified to determine the composition of inorganic compounds as well. A combustion analysis shows that an unknown sample of gas is made of 85.5% carbon and 14.3% hydrogen. What is the empirical formula of the compound
Answer:
Empirical formula: CH₂
Explanation:
We need to find the empirical formula of a compound that has carbon and hydrogen.
To find the empirical formula of any compound, if we have the mass or mass percent, we should follow 3 steps:
1. Calculate the moles, dividing by the atomic weight.
The atomic weight for carbon and hydrogen are 12 g/mol and 1 g/mol, so, doing the division we have:
C = 85.5 / 12 = 7.125
H = 14.3 / 1 = 14.3
2. Determine the number of atoms of each element in the formula
To do this, we just divide the previous moles by the lowest quantity we obtain. In this case, the carbon:
C = 7,125 / 7,125 = 1
H = 14,3 / 7,125 = 2
This means we have 1 atom of carbon and 2 atoms of hydrogen.
3. Write the empirical formula with the previously obtained atoms
Now that we obtained the atoms of each element, we just write the empirical formula with these numbers:
C₁H₂ but we can neglect the number one so:
Empirical formula: CH₂Hope this helps
If 125 mL of 0.56 MH2SO4, is diluted to a volume of 0.250 L, what is the molarity of the resulting solution?
Answer:
0.28M H2SO4
Explanation:
The molarity of a solution is defined as the ratio between the moles of the solute (In this case, H2SO4) and its volume in liters.
In the problem, the volume of the solution is increased from 125mL to 250mL. That means the solution is diluted:
250mL / 125mL = 2 times.
As the solution is diluted 2 times, the concentration is decreased in 2, that is:
0.56M / 2 =
0.28M H2SO4Which of the following does the law of conservation of mass not state?
Answer:
C
Explanation:
Convert 6.71 moles NH3 to number of molecules.
Answer: There are [tex]40.41 \times 10^{23}[/tex] molecules present in 6.71 moles of [tex]NH_{3}[/tex].
Explanation:
Given: Moles of [tex]NH_{3}[/tex] = 6.71 mol
According to the mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{22}[/tex] molecules.
Therefore, molecules present in 6.71 moles are calculated as follows.
[tex]Molecules = moles \times 6.022 \times 10^{23}\\= 6.71 \times 6.022 \times 10^{23}\\= 40.41 \times 10^{23}[/tex]
Thus, we can conclude that there are [tex]40.41 \times 10^{23}[/tex] molecules present in 6.71 moles of [tex]NH_{3}[/tex].
Select the correct image.
The image shows the embryonic development of four different types of vertebrates. Which developmental path is most likely that of a lizard?
Answer:
what image?????
Explanation:
?
Answer:
2nd image/ image B
.
The graph below shows the winter precipitation in Arizona from 1995 to 2002. It also shows the survival rates of Arizona pronghorn fawns for the same period.
• Which two years had the most precipitation? (1point)
• Which two years had the best survival rates for fawns? (1 point)
• Using your knowledge of biotic and abiotic factors and information from the graph, give two reasons why precipitation and fawn population are linked. (2 points)
• Predict what would happen to the fawn population if the precipitation rate continues to go downward in 2003.
Answer:lmk when u have the answer
Explanation:
A. Exothermic
B. Isothermic
C. Endothermic
Answer:
C. Endothermic
Explanation:
Since the products potential energy is higher than the reactants potential energy, it has abosrbed energy, thus making the graph endothermic.
Given the [H+] = 3.89x10^-7M, what is the pOH?
Answer:
7.59
Explanation:
The balanced equation below represents a reaction between propane and oxygen. C3H8 + 5 O2 → 3 CO2 + 4 H2O According to this equation, which ratio of propane to oxygen is correct? 5 grams CO2 1 gram C3H8 3 moles CO2 1 mole C3H8 5 moles O2 1 mole C3H8 3 moles CO2 4 moles H2O
Answer:
5 moles O2 1 mole C3H8
Explanation:
In the question, it is mentioned about the ratio Propane and Oxygen. So the the ration will be 1:5 i.e, 5 moles of O2 1 mole C3H8. There is only one option which mentions both Propane and Oxygen and others doesn't.
What is the OH- ion concentration, in moles per liter, of an aqueous solution with a pH of 7?
A. 1 × 10-14
B. 1 × 10-7
C. 7
D. 14
Answer:
B
Explanation:
the pH scale is based on the function
1x10-14
So since pH is neutral the concentration of OH and H must be equal hence the only option in which the concetration would [OH]{H}= 1x10-14 would be when both are equal so it cannot be a or d and when they are expressed in concetration so the only option is B.
The pH of the solution can be used to give the relation between the pOH and the hydroxide ion concentration. The concentration of hydroxide ions is 1 ×10⁻⁷. Thus, option B is correct.
What is pOH?pOH is the measure of the hydroxide ion in the solution. The hydroxide concentration from pH is related as:
pH = - log [H⁺]
[H⁺] = 10⁻⁷
= 1 × 10⁻⁷
The hydroxide concentration from hydrogen concentration is calculated as:
[H⁺][OH⁻] = 1 × 10⁻¹⁴
[OH⁻] = (1 × 10⁻¹⁴) ÷ (1 × 10⁻⁷)
= 1 ×10⁻⁷
Therefore, option B. 1 ×10⁻⁷ is the hydroxide ion concentration.
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Why the energy difference between the removal of the 2nd and 3rd electrons is smaller than that between the removal of the 3rd the 4th electrons ?
Answer:
See Explanation
Explanation:
Let us remember the fact that electrons actually repel each other in the atom. The more the number of electrons, the greater the repulsion experienced.
Hence, as electrons are successively removed from the atom at each stage of ionization, the magnitude of repulsion due to the presence of more electrons decreases as further electrons are removed, ionization energy consequently increases. Thus, the energy difference between the removal of the 2nd and 3rd electrons is smaller than that between the removal of the 3rd the 4th electrons.
Sometimes, when the removal of the 4th electron has to occur in an inner filled shell which is more stable, a far higher amount of energy is required (a quantum jump) compared to the removal of any of the first three electrons that are present in an incompletely filled outermost shell, E.g in aluminium.
GIVING BRAINLIEST!!!!!!!
PLSSS HELPPP!!!!
Jody had a chicken sandwich and orange juice for lunch. What do you think happens to this food after being passed to the intestines?
A)Both the small and large intestine filter the food from harmful material before they pass into the blood stream.
B)The small intestine absorbs the nutrients into the blood stream and the large intestine absorbs the water.
C)The small intestine turns the food mixture into solid wastes and the large intestine absorbs the nutrients.
D)The small intestine passes oxygen into the food mixture and the large intestine releases it as waste.
Pls no links it’s annoying
Answer:
it's B
Explanation:
the small intestine is know to carrie out most of the digestive process absorbing almost all the nutrients and well the large intestine absorbs water. hope it helps :)
Why do you think certain countries favored military solutions to the great depression while other contries did not
Answer:
The answer is below
Explanation:
Certain countries like Germany under Adolf Hitler favored military solutions to the great depression because the government felt that having a mass production of military weapons and recruitment of unemployed people or citizens into the army would change the dire situation.
On the other hand, countries like the United States did not favor the military solutions but instead choose the NEW DEAL under Franklin D Roosevelt; the reason could be linked to their democratic culture, the isolation belief tendency.
*
Matter cannot be divided indefinitely is part of the:
Answer:
4+4=8
Explanation:
8=X
If a gas exerts 812 torr of pressure at a volume of 31 liters and the temperature of 30 degrees C, how many moles of gas are in the container?
Answer:
1.35 moles
Explanation:
Assuming the gas is ideal, we can solve this problem by using the following equation:
PV = nRTWhere:
P = 812 torr ⇒ 812 / 760 = 1.08 atmV = 31 Ln = ?R = 0.082 atm·L·mol⁻¹·K⁻¹T = 30 °C ⇒ 30 + 273.16 = 303.16 KWe input the data:
1.08 atm * 31 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 303.16 KAnd solve for n:
n = 1.35 molDetergent is an example of what type of compound?
A.) synthetic organic compound
B.) organic compound
C.) chlorofluorocarbon
Answer : A
Explanation : Surface-active compounds/agents (surfactants) Substances which have the effect of reducing the surface tension of a solvent, an example being a detergent/surfactant or soap dissolved in water. ... Both synthetic detergents and soaps are surfactants. Surfactants See "Surface-active compounds/agents".
According to the context, a detergent is an example of a synthetic organic compound.
What is a detergent?They are a group of synthetic organic compounds that have the property of lowering the surface tension of the liquids in which they are dissolved.
These contain surfactant substances that help in penetration, soaking, emulsification, dispersion, solubilization.
Therefore, we can conclude that according to the context, a detergent is an example of a synthetic organic compound.
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How does natural selection, or the concept of “survival of the fittest,” affect us?
Answer:
I hope this helps you! :)
Explanation:
Survival of the fittest" is a popular term that refers to the process of natural selection, a mechanism that drives evolutionary change. Natural selection works by giving individuals who are better adapted to a given set of environmental conditions an advantage over those that are not as well adapted.
a link bot answered my question so let me ask again
Answer:
4 NH3 + 5 O2 = 4 NO + 6 H2O
Explanation:
Balance to have equal atoms on both sides.
5) How many Kilograms are in 12 L of Chlorine Gas?
Answer: 0.03798 kilograms
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given volume}}{\text {Molar Volume}}=\frac{12L}{22.4L}=0.535moles[/tex]
1 mole of chlorine gas [tex](Cl_2)[/tex] weighs = 71 g
Thus 0.535 moles of chlorine gas [tex](Cl_2)[/tex] will weigh = [tex]\frac{71}{1}\times 0.535=37.98g=0.03798kg[/tex] (1kg=1000g)
Thus there are 0.03798 kilograms in 12 L of chlorine gas.
On the pH scale higher numbers indicate ?
Answer:
Higher numbers indicate bases- not acidic/less acidic
Explanation:
Answer:
higher the ph number means stronger base
Explanation:
What is an Independent Variable (IV)? *
here's your answer dear friend❤❤
Which statement most accurately describes the direction of drag
Answer:
Drag opposes forward motion.
Explanation:
Drag always opposes forward motion or slows you down.
what is the chemical name for Se8O7
Answer:
Selenium oxide
Explanation:
What causes elements to react to each other
Answer:
One atom of each element is made up of protons, neutrons, and electrons. The number of electrons determines how an element reacts. The number of protons gives the element its identity. ... They react well with nonmetals because they can easily give up electrons to form ions.
What are carbohydrates?
A. a type of base
B. a type of glyceride
C. a type of macromolecule
D. a type of amino acid
Answer:
a
Explanation:
me say so
Answer:
C
Explanation:
when do electrons release photons
Answer:
Later when they are older
Explanation:
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5. How much heat is evolved when 24.9 g of propanol (C3H7OH) is burned? ΔHcomb = −2010 kJ/mol
The heat is evolved when 24.9 g of propanol (C3H7OH) is burned is 834.15 J
To solve this question, First, we need to find the number of moles present in 24.9 g of propanol.
⇒ Formula
n = M/m................. Equation 1⇒ Where:
n = number of moles M = mass of propanolm = molar mass of propanolFrom the question,
⇒ Given:
M = 24.9 gm = (12×3)+(1×8)+16 = 36+8+16 = 60 g/mol⇒ Substitute these values into equation 1
n = 24.9/60n = 0.415 mol⇒ Finally the heat evolved is
Q = nΔHQ = 0.415(-2010)Q = -834.15 JHence, The heat evolved when propanol is burned is 834.15 J
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What is the single replacement reaction of Zinc + Lead(iv) Chloride
Answer:
[tex]2Zn+PbCl_4\rightarrow 2ZnCl_2+Pb[/tex]
Explanation:
Hello there!
In this case, when referring to single replacement reactions, it is crucial for us to figure out the formula of the starting reactants; thus, we know zinc is Zn and lead (IV) chloride is PbCl₄. In such a way, the reaction proceeds as follows:
[tex]Zn+PbCl_4\rightarrow ZnCl_2+Pb[/tex]
Which must be balanced as shown below:
[tex]2Zn+PbCl_4\rightarrow 2ZnCl_2+Pb[/tex]
Regards!
The enthalpy of a reaction is -1207 kJ/mol. Which of the following best
describes this reaction?
Answer:
D. Exothermic
Explanation:
The enthalpy, ΔH, of a reaction is defined as the change in heat when a reaction occurs.
A reaction with ΔH > 0 is called endothermic and requires energy to be produced
A reaction with ΔH < 0 is called exothermic and produce energy when occurs (An example is the combustion of octane that produce energy that is used in engines to produce movement)
As the enthalpy of the reaction is -1207kJ/mol (ΔH < 0) the reaction is:
D. ExothermicHydrochloric acid reacts with metals to produce hydrogen gas according to
the equation shown below. How many grams of a metal (X) will be
consumed in a reaction if 49.0 mL of 3.0 M HCl are used? The molar mass
of the metal (X) is 72.55 g/mol. Report your answer to the nearest tenth.
2 HCl + X --> XCl2 + H2
Answer:
5.33g of X will be consumed
Explanation:
Based on the reaction, 2 moles of HCl reacts per mole of the metal. To solve this question we must find, as first, the moles of HCl that reacted. With these moles and the chemical equation we can find the moles of X and its mass (With molar mass) as follows:
Moles HCl:
49.0mL = 0.0490L * (3.0mol / L) = 0.147 moles HCl
Moles X:
0.147 moles HCl * (1mol X / 2mol HCl) = 0.0735 moles X
Mass X:
0.0735 moles X * (72.55g / mol) =
5.33g of X will be consumed