Answer:
a. True
Explanation:
Alkanes are chains of carbon atoms surrounded by hydrogen atoms. TRUE.
Alkanes are hydrocarbons, that is, they are organic compounds formed only by carbon and hydrogen. In alkanes, carbon atoms are bonded to each other through single covalent bonds and they are also bonded to hydrogen atoms through the same type of bonds. Alkanes have the general formula CnH2n+2.
Does water mess up carbon dating?
Answer:
THE hard-water effect is a recognized source of error in radiocarbon dating. It causes ages to be over-assessed and arises when the material to be dated, such as mollusc shell or plant, synthesizes its skeleton under water and so uses bicarbonate derived in part from old, inert sources.
https://www.nature.com/articles/240460a0#:~:text=THE%20hard%2Dwater%20effect%20is,part%20from%20old%2C%20inert%20sources.
Answer:
In radiocarbon dating, the hard-water effect has been identified as a cause of inaccuracy. It occurs when the item to be dated, such as a mollusk shell or a plant, synthesizes its skeleton underwater and therefore utilizes bicarbonate obtained in part from ancient, inert sources, resulting in the overestimation of ages.
OAmalOHopeO
5. A beam of photons with a minimum energy of 222 kJ/mol can eject electrons from a potassium surface. Estimate the range of wavelengths of light that can be used to cause this phenomenon. Show your calculations with units of measure (dimensional analysis) and briefly explain your reasoning.
Answer: The range of wavelengths of light that can be used to cause given phenomenon is [tex]8.953 \times 10^{21} m[/tex].
Explanation:
Given: 222 kJ/mol (1 kJ = 1000 J) = 222000 J
Formula used is as follows.
[tex]E = \frac{hc}{\lambda}[/tex]
where,
E = energy
h = Planck's constant = [tex]6.625 \times 10^{-25} Js[/tex]
c = speed of light = [tex]3 \times 10^{8} m/s[/tex]
Substitute the values into above formula as follows.
[tex]E = \frac{hc}{\lambda}\\222000 J = \frac{6.625 \times 10^{-34}Js \times 3 \times 10^{8} m/s}{\lambda}\\\lambda = 8.953 \times 10^{21} m[/tex]
Thus, we can conclude that the range of wavelengths of light that can be used to cause given phenomenon is [tex]8.953 \times 10^{21} m[/tex].
what will the time for half life of the first order reaction?
Answer:
The half-life of a reaction is the time required for the reactant concentration to decrease to one-half its initial value. The half-life of a first-order reaction is a constant that is related to the rate constant for the reaction: t1/2 = 0.693/k. Radioactive decay reactions are first-order reactions.
Explanation:
The half-life of a reaction is the time required for the reactant concentration to decrease to one-half its initial value. The half-life of a first-order reaction is a constant that is related to the rate constant for the reaction: t1/2 = 0.693/k. Radioactive decay reactions are first-order reactions.
Calculate percent yield when you start with 0.78 grams of camphor and end with 0.23 grams of iso/borneol. The molecular weight of camphor is 152.23 g/mol, and the molecular weight of iso/borneol is 154.25 g/mol.
Answer:
29.1%
Explanation:
First we convert 0.78 g of camphor to moles, using its molar mass:
0.78 g ÷ 152.23 g/mol = 0.00512 mol camphorThen we convert 0.23 g of isoborneol to moles, using its molar mass:
0.23 g ÷ 154.25 g/mol = 0.00149 mol isoborneolFinally we calculate the percent yield:
0.00149 mol / 0.00512 mol * 100% = 29.1%Liquid nitrogen boils at –195.8°C. Express the boiling point of liquid nitrogen in kelvin
Answer:
[tex]\boxed {\boxed {\sf 77.35 \ K}}[/tex]
Explanation:
The Celsius and Kelvin scales are used to measure the temperature of matter. Their scales and unit differences are the same (1 K increase = 1 °C increase), but they have different starting points.
So, the conversion is quite simple and only requires addition because of the different starting points. The formula is:
[tex]T_K = T_C+ 273.15[/tex]
The boiling point of liquid nitrogen is -195.8 °C. We can substitute this value into the formula.
[tex]T_K= -195.8 + 273.15[/tex]
[tex]T_K= 77.35 K[/tex]
The boiling point of liquid nitrogen is 77.35 Kelvin.
A molecule of acetone and a molecule of propyl aldehyde are both made from 3 carbon atoms, 6 hydrogen atoms, and 1 oxygen atom. The molecules differ in their arrangement of atoms. How do formulas for the two compounds compare? Both compounds have the same molecular formula, but have unique structural formulas. Both compounds have unique molecular formulas and structural formulas. Both compounds have the same structural formula, but have unique molecular formulas.
Explanation:
The structures of both acetone and propanal are shown below:
In the formula of propanal there is -CHO functional group at the end.
In acetone -CO- group is present in the middle that is on the second carbon.
The molecular formula is C3H6O.
Both have same molecular formula but different structural formulas.
give reason why mendeleev's definition of transition elements is no longer acceptable
Hydrogen is manufactured on an industrial scale by this sequence of reactions: Write an equation that gives the overall equilibrium constant in terms of the equilibrium constants and . If you need to include any physical constants, be sure you use their standard symbols, which you'll find in the ALEKS Calculator.
The question is incomplete. The complete question is :
Hydrogen is manufactured on an industrial scale by this sequence of reactions:
[tex]$CH_3(g) + H_2O(g) \rightleftharpoons CO(g) + 3H_2(g ) \ \ \ \ \ \ \ \ \ \ K_1$[/tex]
[tex]$CO(g) + H_2O(g) \rightleftharpoons CO_2(g) + H_2(g) \ \ \ \ \ \ \ \ \ \ \ \ K_2$[/tex]
The net reaction is :
[tex]$CH_4(g) + 2H_2O(g) \rightleftharpoons CO_2(g) + 4H_2(g) \ \ \ \ \ \ \ \ \ K$[/tex]
Write an equation that gives the overall equilibrium constant [tex]K[/tex] in terms of the equilibrium constants [tex]K_1[/tex] and [tex]K_2[/tex]. If you need to include any physical constants, be sure you use their standard symbols, which you'll find in the ALEKS Calculator.
Solution :
[tex]$CH_3(g) + H_2O(g) \rightleftharpoons CO(g) + 3H_2(g ) \ \ \ \ \ \ \ \ \ \ K_1$[/tex]
[tex]$K_1 = \frac{[CO][H_2]^3}{[CH_4][H_2O]}$[/tex] ...............(1)
[tex]$CO(g) + H_2O(g) \rightleftharpoons CO_2(g) + H_2(g) \ \ \ \ \ \ \ \ \ \ \ \ K_2$[/tex]
[tex]$K_2 = \frac{[CO_2][H_2]}{[CO][H_2O]}$[/tex] ...................(2)
[tex]$CH_4(g) + 2H_2O(g) \rightleftharpoons CO_2(g) + 4H_2(g) \ \ \ \ \ \ \ \ \ K$[/tex]
[tex]$K=\frac{[CO_2][H_2]^4}{[CH_4][H_2O]^2}$[/tex]
On multiplication of equation (1) and (2), we get
[tex]$K_1 \times K_2=\frac{[CO][H_2]^3}{[CH_4][H_2O]} \times \frac{[CO_2][H_2]}{[CO][H_2O]}$[/tex]
[tex]$K_1K_2=\frac{[CO_2][H_2]^4}{[CH_4][H_2O]^2}$[/tex] .................(4)
Comparing equation (3) and equation (4), we get
[tex]$K=K_1K_2$[/tex]
Which of state of matter has no definite shape but does have a definite volume?
A. Liquid
O B. Element
C. Solid
D. Gas
Answer:
A. Liquid .
Explanation:
Hello there!
In this case, according to the given information, it turns possible for us to to infer that the answer is A. Liquid because solids have both definite shape and volume and gases have no definite neither volume nor shape because they depend on the container.
This is this way because the molecules in the liquid are able to vibrate and slowly move around unlike gases and solids whereas molecules readily move and merely vibrate respectively.
Regards!
Calculate the percent dissociation of crotonic acid (C,H,CO,H) in a 0.63 mM aqueous solution of the stuff.
Answer:
16%
Explanation:
Crotonic acid : C₃H₅CO₂H
C₃H₅CO₂H ⇄ C₃H₅CO₂⁻ + H⁺
C O O
where : C = C ( 1 - ∝ ) , O = C∝
also: Ka = C∝² / ( 1 - ∝ ) ---- ( 1 )
From Alexa data resource :
Pka = 4.69 , [ Ka = 2.04 * 10^-5 = C∝² / ( 1 - ∝ ) ]
back to equation 1
2.04 * 10^-5 = [ ( 0.63 * 10^-3 ) * ∝² / ( 1 - ∝ ) ] ----- ( 2 )
∴ ∝² / ( 1 - ∝ ) = 3.24 * 10⁻²
Resolving equation above
∝ = 0.1645 = 16.45%
An electrolysis reaction is
A)
exothermic.
B)
hydrophobic.
C)
spontaneous.
D)
non-spontaneous.
Answer:
the electrolysis reaction is a non- spontaneous reaction
Explanation:
Since electrons flow from it, the anode in an electrolytic cell is positive, while the cathode is negative when electrons flow into it. The device functions like a galvanic cell in that direction. In an electrolytic cell, an external voltage is applied and that is what causes a non spontaneous reaction
Calculate the mass percent of KCl in a 0.35 m solution of KCl in water. Assume that the density of water is 1.00 g/mL.
Answer:
Mass percent of KCl is 2.61 %
Explanation:
Our solute is KCl
Our solvent is water
m means molality (moles of solute in 1kg of solvent)
1 kg = 1000 g
0.35 m means that 0.35 moles of KCl are contained in 1000g of solvent
We determine mass of solute: 0.35 mol . 74.55 g/mol = 26.09 g
Total mass of solution is: mass of solute + mass of solvent
26.09 g + 1000 g = 1026.09 g
Mass percent of KCl = (mass of KCl/ mass of solution) . 100
(26.09 / 1026.09) . 100 = 2.61 %
Classify the following as either solutions or colloids. If a colloid, name the type of colloid and identify both the dispersed and the dispersing phases.
a. glucose in water
b. smoke in air
c. carbon dioxide in air
d. milk
Answer:
a. glucose in water( solution)
b. smoke in air (colloids)
c. carbon dioxide in air (solution)
d. milk( colloids)
Explanation:
A solution is said to be formed when a solute dissolves in a solvent to form a homogeneous mixture. The solute particles are less than 10^-9m in size. Familiar solutions are those where the solute are dissolved in a liquid solvent. When the liquid water, the solution is known as an aqueous solution. A typical example is (glucose in water). In some other cases, the apparent solution of a solute in a solvent is accompanied by a chemical reaction and this is often known as a chemical reaction. A typical example is (carbon dioxide in air).
Colloids are also known as false solutions. Here, the individual solute particles are larger than the particles of the true solution, but not large enough to be seen by the naked eye. When a light beam is placed beside a beaker containing a colloid, the light rays of the beam can be clearly seen. This shows that it exhibits the Tyndall effect while a solution dosent exhibit such.
In a colloid, the liquid solvent is more appropriately know as the DISPERSION medium while the solid solute particles constitute the DISPERSED substance. This can either be solid, liquid or gas.
For example:
--> smoke in air : Dispersion medium is gas while the dispersed substance is solid.
--> milk: Dispersion medium is liquid while the dispersed substance is liquid.
Determine whether the reaction will be spontaneous at high temperatures only, at low temperatures only, at all temperatures, or no temperatures. (HINT: Use your chemical sense and your real-world knowledge to predict the signs of delta Hrxn & delta Srxn)
4Fe(s) + 3O2(g) ----> 2Fe2O3(s) [rust]
Circle one:High T, Low T, All T, No T
Answer:
The rusting of iron is spontaneous at low temperatures.
Explanation:
The given chemical reaction is:
4Fe(s) + 3O2(g) ----> 2Fe2O3(s) [rust]
The rusting of iron is a chemical reaction in which iron reacts with oxygen in presence of moisture and forms iron oxide.
This reaction takes place in a faster rate when there is low temperatures in the atmosphere.
When temperature is low, the moisture in the atmosphere is more and hence, rate of rusting is more.
explain in brief how some bacteria cause tooth cavities
Answer:
because some bacteria change the ph of the teeth and leads to tooth cavitiew
Write the equation for the neutralization reaction in which barium chloride is the salt formed. Show the reaction in which the fully protonated acid reacts with the base to form the salt indicated. Use the smallest integer coefficients possible. (Use the lowest possible coefficients. Omit states of matter.)
Answer:
2 HCl + Ba(OH)₂ ⇒ BaCl₂ + 2 H₂O
Explanation:
In a complete neutralization reaction, an acid reacts with a base to form neutral salt and water. To form barium chloride, hydrochloric acid (acid) reacts with barium hydroxide (base). The balanced chemical equation is:
2 HCl + Ba(OH)₂ ⇒ BaCl₂ + 2 H₂O
At 298 K, ∆H = -314 kJ/mol and ∆S = -0.372 kJ/(K•mol). What is the Gibbs free energy of the reaction?
Answer:
-203 kJ/mol
Explanation:
Step 1: Given data
Standard enthalpy of the reaction (ΔH°): -314 kJ/molStandard entropy of the reaction (ΔS°): -0.372 kJ/K.molAbsolute temperature (T): 298 KStep 2: Calculate the standard Gibbs free energy of the reaction (ΔG°)
We will use the following expression.
ΔG° = ΔH° - T × ΔS°
ΔG° = (-314 kJ/mol) - 298 K × (-0.372 kJ/K.mol) = -203 kJ/mol
By convention, when ΔG° < 0, the reaction is spontaneous.
For a gas sample containing equimolar amounts of carbon monoxideand heliumat 300 K, heliumhas _____________average speed and _____________ average kinetic energy compared tocarbon monoxidegas.a.a lower; the same b. the same; the same c. a higher; the same d. a higher; higher
Answer:
Option C (a higher; the same) is the appropriate response.
Explanation:
Given:
Temperature,
T = 300 K (both [tex]N_2[/tex] and [tex]H_2[/tex])
As we know,
Average speed of a molecule,
⇒ [tex]\bar v=\sqrt{\frac{8RT}{\pi M} }[/tex]
Thus, the average speed of [tex]N_2[/tex] will be lower as its molar mass is greater than [tex]H_2[/tex].
Now,
⇒ [tex]Average \ kinetic \ energy = \frac{3}{2} \ KT[/tex] (not depend on molar mass)
Hence, it will be the same.
The other three alternatives aren't connected to the scenario given. So the above is the correct answer.
4. A salvage operator recovered coins believed to be gold. A sample weighed 385.000g and has a volume of 20.0mL. Were the coins gold (Density= 19.3g/mL) or yellow brass (Density =8.47g/mL)? Show your calculation and explain your answer.
Answer:
Gold
Explanation:
We are given that
Mass of sample ,m=385 g
Volume ,V=20mL
We have to find the coin is gold or yellow brass.
We know that
Density=[tex]\frac{Mass}{volume}[/tex]
Using the formula
[tex]Density=\frac{385}{20}g/mL[/tex]
[tex]Density=19.25g/mL[/tex]
[tex]Density\approx 19.3g/mL[/tex]
Density of coin=19.3g/mL
Density of gold=19.3g/mL
Hence, the coin is gold.
it takes 513 kj to remove a mole of electrons from the atoms at the surface of a piece of metal. how much energy does it take to remove a single electron from n atom at the surface of the metal
Answer:
The right solution is "[tex]8.5\times 10^{-19} \ joule[/tex]".
Explanation:
As we know,
1 mole electron = [tex]6.023\times 10^{23} \ no. \ of \ electrons[/tex]
Total energy = [tex]513 \ KJ[/tex]
= [tex]513\times 1000 \ joule[/tex]
For single electron,
The amount of energy will be:
= [tex]\frac{513\times 1000}{(6.023\times 10^{23})}[/tex]
= [tex]8.5\times 10^{-19} \ joule[/tex]
Nitrogen monoxide and water react to form ammonia and oxygen, like this: (g)(g)(g)(g) Write the pressure equilibrium constant expression for this reaction.
Answer:
Kp = \frac{P(NH_{3}) ^{4} P(O_{2}) ^{5}}{P(NO) ^{4} P(H_{2}O)^{6}}
Explanation:
First, we have to write the balanced chemical equation for the reaction. Nitrogen monoxide (NO) reacts with water (H₂O) to give ammonia (NH₃) and oxygen (O₂), according to the following:
NO(g) + H₂O(g) → NH₃(g) + O₂(g)
To balance the equation, we add the stoichiometric coefficients (4 for NH₃ and NO to balance N atoms, then 6 for H₂O to balance H atoms and then 5 for O₂ to balance O atoms):
4 NO(g) + 6 H₂O(g) → 4 NH₃(g) + 5 O₂(g)
All reactants and products are in the gaseous phase, so the equilibrium constant is expressed in terms of partial pressures (P) and is denoted as Kp. The Kp is expressed as the product of the reaction products (NH₃ and O₃) raised by their stoichiometric coefficients (4 and 5, respectively) divided into the product of the reaction reagents (NO and H₂O) raised by their stoichiometric coefficients (4 and 6, respectively). So, the pressure equilibrium constant expression is written as follows:
[tex]Kp = \frac{P(NH_{3}) ^{4} P(O_{2}) ^{5}}{P(NO) ^{4} P(H_{2}O)^{6}}[/tex]
A sample of oxygen gas has a volume of 89.6 L at STP. How many moles of oxygen gas are present ?
Answer:
89,6/22,4 =4(mol)
Explanation:
There are approximately 1.089 moles of oxygen gas present in the sample at STP.
At STP (Standard Temperature and Pressure), the conditions are defined as follows:
Temperature (T) = 0 degrees Celsius = 273.15 Kelvin
Pressure (P) = 1 atmosphere (atm) = 101.325 kPa = 1013.25 hPa
Now, to find the number of moles of oxygen gas (O2) present in the sample, we can use the ideal gas law:
PV = nRT
Where:
P = pressure (in atm)
V = volume (in liters)
n = number of moles
R = ideal gas constant = 0.0821 L.atm/(mol.K)
T = temperature (in Kelvin)
Given:
V = 89.6 L (volume at STP)
T = 273.15 K (STP temperature)
Let's plug in the values and solve for n (number of moles):
n = PV / RT
n = (1 atm) × (89.6 L) / (0.0821 L.atm/(mol.K) × 273.15 K)
n = 1.089 moles
So, there are approximately 1.089 moles of oxygen gas present in the sample at STP.
To know more about oxygen gas:
https://brainly.com/question/31842859
#SPJ2
Identify the highest energy molecular process that occurs when a molecule absorbs a microwave photon.
The question is incomplete, the complete question is;
Identify the highest energy molecular process that occurs when a molecule absorbs a microwave photon
a) electronic excitation
b) bond breakage
c) molecular vibration
d) molecular rotation
Answer:
molecular rotation
Explanation:
Microwaves are part of the electromagnetic spectrum. They are lower energy, lower frequency radiation.
When molecules absorb infrared radiation, they transition between the rotational states of the molecule.
Hence, the highest energy molecular process that occurs when a molecule absorbs a microwave photon is molecular rotation.
for a reaction, ΔH= 206 kJ/mol and ΔS=0.215 kj/(k•mol). At what temperatures is this reaction spontaneous?
Answer:
When the temperature of the reaction is > 958.1K
Explanation:
A reaction is spontaneous when ΔG < 0.
We can solve this question finding the temperature at which ΔG < 0 using the equation:
ΔG = ΔH - TΔS
As ΔG < 0
ΔH < TΔS
206kJ/mol < T*0.215kJ/K.mol
958.1K < T
When the temperature of the reaction is > 958.1K, the reaction is spontanous because ΔG < 0.
_________one moleculetwo moleculesone moletwo moles of H2(g) reacts with _________one moleculetwo moleculesone moletwo moles of F2(g) to form _________one moleculetwo moleculesone moletwo moles of HF(g).
Answer:
The reaction between hydrogen and fluorine.
Explanation:
The balanced chemical equation of the reaction is:
[tex]H_2(g)+F_2(g)->2HF(g)[/tex]
From the balanced chemical equation, it is clear that:
1 mole of [tex]H_2[/tex] gas reacts with one mole of [tex]F_2(g)[/tex] and forms 2 moles of HF(g).
What is the major product in this reaction
Answer:
I think option A is right answer
dentify the correct formula for the following ionic compounds. - sodium chloride - magnesium chloride - calcium oxide - lithium phosphide - aluminum sulfide - calcium nitride A. SCl B. LiP 3 C. AlS D. Li 3P E. CaN F. CaO G. Ca 3N 2 H. MgCl 2 I. NaCl J. CaO 2 K. CaN 2 L. LiP M. MnCl 2 N. Al 2S 3 O. AlS 3
Explanation:
The chemical formula of an ionic compound can be written by using the symbols of the respective cations and anions.
The overall charge on the molecule should be zero.
Hence, the total charge of cations=total charge of anions.
The symbols of the given molecules are shown below:
sodium chloride ---- NaCl
magnesium chloride ---[tex]MgCl_2[/tex]
calcium oxide ---- CaO
lithium phosphide----[tex]Li_3P[/tex]
aluminum sulfide ----- [tex]Al_2S_3[/tex]
calcium nitride---- [tex]Ca_3N_2[/tex]
A chemical reaction was carried out by mixing 25 g of pure CaCO3 and 0.75 mole of pure HCl to give CaCl2, H2O and CO2. a. Which one is the limiting reactant and why? b. Calculate the mass of CaCl2 produced. c. How many number of water molecules are formed? d. Calculate the volume of CO2 gas liberated at STP. e. What mass of NaOH is required to absorb the whole CO2 produced in the reaction?
hola, esta pregunta es bastante difícil pero está bien, no lo sé, lo siento :) :)
All the options are solved and answer is written below
What is a Chemical Reaction ?A reaction between two or more compounds to form products made after chemical change is called a chemical reaction.
It is given that
A chemical reaction was carried out by mixing 25 g of pure CaCO₃ and 0.75 mole of pure HCl
CaCl₂ , H₂O and CO₂ are the products obtained.
CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O
Mole ratio CaCO₃ : HCl : CaCl₂ : H₂O = 1 : 2 : 1 : 1
Molar mass of CaCO₃ = 100 g/mol
Molar mass of HCl = 36.5 g/mol
Molar mass of H₂O = 18 g/mol
Molar mass of CaCl₂= 110.98 g/mol
Moles of CaCO₃ = 25/100 = 0.25 moles
Moles of HCl present = 0.75 mole
For 0.25 moles of CaCO₃ 0.5 moles of HCl is required , as the moles of HCl is present in excess therefore
a. CaCO₃ is the limiting reactant
b. mass of CaCl₂ produced
Moles of CaCl₂ produced = 0.25 moles
1 mole means 110.98 gm
0.25 mole means 0.25* 110.98 = 27.74 gm
c. moles of water molecules formed
for 0.25 moles of CaCO₃ 0.25 moles of water will be formed
d.Volume of Co produced at STP
PV = nRT
P= 1 atm
V=?
R = 0.0821 atm L/K/mol
V = 0.25 * 0.0821 * 273 /1
V = 5.6 liter
e. The mass of NaOH required to absorb CO₂ produced in the reaction
Ratio of NaOH:CO₂ = 2 :1
0.5 moles will be required , i.e.
0.5 *40
20 grams of NaOH will be required.
To know more about Chemical Reaction
https://brainly.com/question/23919704
#SPJ2
Define the following type of bonds..
Ionic bond.
Covalent bond.
Co ordinate bond separately .
Answer:
Ionic bond: Ionic bonds are bonds involving the attraction between oppositely-charged ions.
Covalent bond: Covalent bonds form when electrons are shared between atoms and are attracted by the nuclei of both atoms.
Co ordinate bond separately: a covalent bond in which both electrons are provided by one of the atoms. dative bond.
Explanation:
Hope this helps!
6.50 g of a certain Compound x, known to be made of carbon, hydrogen and perhaps oxygen, and to have a molecular molar mass of 128. g/mol, is burned completely in excess oxygen, and the mass of the products carefully measured: product carbon dioxide water mass 22.35 g 3.66 g Use this information to find the molecular formula of x
Answer:
[tex]C_{10}H_8[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to find the molecular formula of the given compound by firstly calculating both moles and grams of carbon in carbon dioxide and hydrogen in water, as the only sources of these elements derived from the compound x due to its combustion:
[tex]n_C=22.35gCO_2*\frac{1molCO_2}{44.01gCO_2}*\frac{1molC}{1molCO_2}=0.51molC\\\\m_C=0.51molC*\frac{12.01gC}{1molC} =6.10gC[/tex]
[tex]n_H=3.66gH_2O*\frac{1molH_2O}{18.02gH_2O}*\frac{2molH}{1molH_2O}=0.41molH\\\\m_H=0.41molH*\frac{1.01gH}{1molH}=0.41g[/tex]
Now, since the addition of carbon and hydrogen is about 6.50 grams, we infer the compound has no oxygen, that is why we now set the mole ratios in the empirical formula for both C and H as shown below:
[tex]C:\frac{0.51mol}{0.41mol}= 1.24\\\\H:\frac{0.51mol}{0.51mol}= 1\\\\C_{1.24}H[/tex]
Yet it cannot be decimal, that is why we multiply by 4 to get the correct whole-numbered empirical formula:
[tex]C_5H_4[/tex]
Whose molar mass is 64.09 g/mol, which makes the ratio of molar masses:
[tex]\frac{128.g/mol}{64.09g/mol} =2[/tex]
Therefore, the molecular formula is twice the empirical one:
[tex]C_{10}H_8[/tex]
Regards!
