Answer:
Compound X has a molar mass of 316.25 g*mol^-1 and the following composition:
element & mass %
phosphorus & 39.18%
sulfur & 60.82%
Write the molecular formula of X.
Explanation:
The given molecule of phosphorus and sulfur has molar mass --- 316.25 g.
Empirical formula calculation:
element: phosphorus sulfur
co9mposition: 39.185% 60.82%
divide with
atomic mass: 39.185/31.0 g/mol 60.82/32.0g/mol
=1.26mol 1.90mol
smallest mole ratio: 1.26mol/1.26mol =1 1.90mol/1.26 mol =1.50
multiply with 2: 2 3
Hence, the empirical formula is:
P2S3.
Mass of empirical formula is:
158.0g/mol
Given, molecule has molar mass --- 316.25 g/mol
Hence, the ratio is:
316.25g/mol/158.0 =2
Hence, the molecular formula of the compound is :
2 x (P2S3)
=[tex]P_4S_6[/tex]
from the following equation in which decomposition of CaCO3 takes place, give your justification. CaCO3 gives Ca +CO2
Answer:
CaCO₃(s) => CaO(s) + CO₂(g) ... GpIIA Decomp
Explanation:
Metallic Carbonates decompose into a metallic oxide and carbon dioxide.
Examples:
Na₂CO₃(s) => Na₂O(s) + CO₂(g) ... GpIA Decomp
MgCO₃(s) => MgO(s) + CO₂(g) ... GpIIA Decomp
A chemistry grad student measures the performance of the new pump in his lab. The result is:Convert to
Answer:
The correct answer is - 0.0188 mJ*s^-1.
Explanation:
In order to convert the kPA value to PA value--
and then convert PA unit to 1 kgm^-1s^-2
And in finally convert mm to m
The value that come should be convert from kgm^2s^-2 to and then convert J to mJ or kJ by dividing 100 or 100 subsequently.
As no question given this method can be followed for the answer.
A chemist fills a reaction vessel with 9.47 atm nitrogen monoxide (NO) gas, 2.61 atm chlorine (C12) gas, and 8.64 atm nitrosyl chloride (NOCI) gas at a temperature of 25.0°C. Under these conditions, calculate the reaction free energy AG for the following chemical reaction:
2NO(g) + Cl2(g) = 2NOCI (g)
Use the thermodynamic information in the ALEKS Data tab. Round your answer to the nearest kilojoule.
Answer: The Gibbs free energy change of the reaction is 2.832 kJ.
Explanation:
The relationship between Gibbs free energy change and reaction quotient of the reaction is:
[tex]\Delta G^o=-RT\ln Q_p[/tex]
where,
[tex]\Delta G^o[/tex] = Gibbs free energy change
R = Gas constant = 8.314 J/mol.K
T = temperature = [tex]25^oC=298K[/tex]
[tex]Q_p[/tex] = reaction quotient = [tex]\frac{p_{NOCl}^2}{(p_{NO}^2)\times (p_{Cl_2})}[/tex]
We are given:
[tex]p_{NOCl}=8.64atm\\p_{NO}=9.47atm\\p_{Cl_2}=2.61atm[/tex]
Putting values in above equation, we get:
[tex]\Delta G^o=-(8.314)\times 298K\times \ln (\frac{(8.64)^2}{(9.47)^2\times (2.61)})\\\\\Delta G^o=-8.314\times 298\times (-1.143)[/tex]
[tex]\Delta G^o=2831.86J=2.832kJ[/tex] (Conversion factor: 1 kJ = 1000 J)
Hence, the Gibbs free energy change of the reaction is 2.832 kJ.
The titration of a weak acid with a strong base is a common exercise in chemistry labs. We have looked at all of the individual types of calculations needed to determine the pH at any point of a titration. Consider the titration of 0.100 L of 0.300 M acetic acid with 2.00 M NaOH. What type of calculation will we be performing at the following points of the titration curve
Answer:
1. Weak acid calculation
2. Strong base calculation
3. Strong base calculation
4. Strong base calculation
Explanation:
1. Zero equivalents of base added
2. 0.15 equivalents of base added
3. One equivalent of base added
4. 1.75 equivalents of base added
The equivalents of acetic acid are:
0.100L * (0.300mol/L) = 0.0300 moles of acetic acid = 0.0300Eq.
1. With Zero equivalents of base added you will calculate pH using weak acid calculation because you have only acetic acid (Weak acid) in the solution.
2. When 0.15 equivalents of base are added all the acid reacted and 0.15-0.03 = 0.12 equivalents of Strong base are in excess. With these equivalents and the volume we can find pH using strong base calculation.
3 and 4. As with 0.15 eq. added the 1 eq. and 1.75 eq. produce an excess of strong base and the pH must be calculated by using strong base calculation
The main importance of the titration curve is that it is used show how the pH of the solution changes as a titrant is added to the solution.
What is a titration curve?A titration curve is a plot of pH of the system against the volume of titrant added. The question is incomplete but I will try to explain what a titration curve is.
The main importance of the titration curve is that it is used show how the pH of the solution changes as a titrant is added to the solution.
Learn more about a titration curve: https://brainly.com/question/4260635
ELECTROLYSIS OF MOLTEN NaCl IS DONE IN A DOWNS CELL OPERATING AT 7.0 VOLTS AND 4.0X10^4A. HOW MUCH Na(s) AND Cl2(g) CAN BE PRODUCED IN 8 HOURS IN SUCH A CELL?
Answer:
Mass of sodium produced = 2.74 × 10⁵ g of Na
Mass of chlorine produce = 4.24 × 10⁵ g of Cl₂
Explanation:
In the electrolysis of molten NaCl as described above, the quantity of charge used is given by the formula, Q = I × t
Where I isnthe current passed in amperes and t is time in seconds.
Q = 4.0 × 10⁴ A × (8 × 60 × 60) s = 1.152 × 10⁹ C
Equation for the discharge of sodium is; Na+ + e- ---> Na (s)
One mole of electrons is required to discharge one mole of Na
One mole of electron = 1 faraday = 96500 C
One mole of Na has a mass of 23 g
96500 C produces 23 g of Na
1.152 × 10⁹ C will produce 23 g × 1.152 × 10⁹ C / 96500 C = 2.74 × 10⁵ g of Na
Equation for the discharge of chlorine gas is; 2 Cl- ---> Cl₂(g) + 2e-
Two mole of electrons are required to discharge one mole of chlorine gas
Two moles of electron = 2 faraday = 2 × 96500 C = 193000
One mole of Cl₂ has a mass of 71 g
193000 C produces 71 g of Cl₂
1.152 × 10⁹ C will produce 71 g × 1.152 × 10⁹ C / 193000 C = 4.24 × 10⁵ g of Cl₂
The amount of Na produced is 274551 g and the amount of Cl₂ produced is 423763.5 g.
Current passed through the cell = [tex]4.0\times10^4 A[/tex]
Time = 8 Hours
We have to calculate the amount of Na and [tex]Cl_2[/tex] produced in 8 hours in the downs cell.
What is a down cell?The Downs process is an electrochemical method for the commercial preparation of metallic sodium, in which molten NaCl is electrolyzed in a special apparatus called the Downs cell.
The total charge passed through the cell is calculated by the given formula as
Charge(Q) = Current(I) × time(t)
Q = [tex]4.0\times10^4 A \times t[/tex]
[tex]t = 8 \times 60\times 60[/tex] sec
t = 28800 sec
Q = [tex]4.0\times10^4 A \times 28800[/tex] sec
Q = [tex]115200\times 10^4 A\ sec[/tex]
We know that, Ampere = Coulombs per sec
Q = [tex]115200\times 10^4\ C[/tex]
1 mol of electrons 96500 C charge
Therefore, the number of mols of electrons carries this [tex]115200\times 10^4\ C[/tex] charge = [tex]\frac{115200\times10^4}{96500}[/tex] = 1.1937 × 10⁴ = 11937 mol electrons
In the Down's cell
Half cell reactions are:
Reduction half-reaction: [tex]2Na^+(aq)+2e^- \to 2Na(s)[/tex]
Oxidation half-reaction: [tex]2Cl^-(aq)\to Cl_2(g) + 2e^-[/tex]
We know that no. of moles = [tex]\frac{given \ mass}{molar \ mass}[/tex]
Molar mass of Na = 23 g/mol
The mass of Na formed = 11937 mol × 23 g/mol = 274551 grams
The molar mass of Cl₂ = 71 g/mol
The mass of Cl₂ = [tex]\frac{11937}{2}\times 71 = 423763.5 \ grams[/tex]
Hence, the amount of Na produced is 274551 g and the amount of Cl₂ produced is 423763.5 g.
To learn more about electrochemistry, click here:
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Which mechanisms is most significant in returning the ion concentrations to the resting state?
Answer:
Active transport by the Na+-K+ pump
Explanation:
Active transport by the Na+-K+ pump
Maintenance (and restoration) of the resting ion concentrations depends on the Na+-K+ pump. Once gated ion channels are closed, the combined action of the pump and ion leakage (particularly that of K+) establishes a resting membrane potential in a typical neuron of around âˆ'70 mV.
Excited sodium atoms may emit radiation having a wavelength of 589nm. a) What is the wavelength in meters
Answer: When excited sodium atoms may emit radiation having a wavelength of 589nm. It's wavelength in meters is [tex]589 \times 10^{-9} m[/tex].
Explanation:
Given: Wavelength = 589 nm
It is known that,
[tex]1 nm = 10^{-9} m[/tex]
Hence, 589 nm is converted into meters as follows.
[tex]589 nm = 589 nm \times \frac{10^{-9}m}{1 nm}\\= 589 \times 10^{-9} m[/tex]
Thus, we can conclude that when excited sodium atoms may emit radiation having a wavelength of 589nm. It's wavelength in meters is [tex]589 \times 10^{-9} m[/tex].
Many chemistry problems result in equations of the form
1.77 X100.298-z)
When this equation is solved, the two values of the unknown are ________ and ________
Answer:
When this equation is solved, the two values of the unknown are 0.0643 and -0.082
Explanation:
Given
[tex]1.77 * 10^{-2} = \frac{x^2}{0.298 - x}[/tex] --- the actual equation
Required
The values of x
We have:
[tex]1.77 * 10^{-2} = \frac{x^2}{0.298 - x}[/tex]
Cross Multiply
[tex]1.77 * 10^{-2} * (0.298 - x)= x^2[/tex]
Multiply both sides by 100
[tex]1.77 * (0.298 - x)= 100x^2[/tex]
Open bracket
[tex]0.52746 - 1.77x= 100x^2[/tex]
Rewrite as:
[tex]100x^2 + 1.77x - 0.52746 =0[/tex]
Using quadratic formula:
[tex]x = \frac{-b \± \sqrt{b^2 - 4ac}}{2a}[/tex]
Where:
[tex]a = 100; b = 1.77; c = -0.52746[/tex]
So, we have:
[tex]x = \frac{-1.77 \± \sqrt{1.77^2 - 4*100*- 0.52746 }}{2*100}[/tex]
[tex]x = \frac{-1.77 \± \sqrt{214.1169}}{2*100}[/tex]
[tex]x = \frac{-1.77 \± 14.63}{200}[/tex]
Split
[tex]x = \frac{-1.77 + 14.63}{200}\ or\ x = \frac{-1.77 - 14.63}{200}[/tex]
[tex]x = \frac{12.86}{200}\ or\ x = \frac{-16.40}{200}[/tex]
[tex]x = 0.0643\ or\ x = -0.082[/tex]
Increasing the thermal energy of a solution means you are __ it and increasing the __energy.
Answer:
heating, thermal
Explanation:
the more molecules present, the greater amount from any given source increases the temperature as well as the thermal energy.
Determine whether methylcyclohexane contains a chiral center. _____ How many different substituents do you count at atom
Answer:
methylcyclohexane does not possess a chiral center
Explanation:
A molecule is said to possess a chiral center if one or more of the atoms in the molecule is bonded to four different atoms or groups.
If we look at methylcyclohexane, none of the carbon atoms in the molecule is bonded to four different atoms or groups hence the molecule contains no chiral centers and will not exhibit optical isomerism.
So, methylcyclohexane has a plane of symmetry thus it is an achiral molecule.
Excluding any secondary chemical reactions,
which would be more effective as an antifreeze; a
solution containing
Select one:
25m CH3OH
the combination of 25m CH3OH and 25m
KCI.
O 25m KCI.
O
none of these
Answer:
Excluding any secondary chemical reactions,
which would be more effective as an antifreeze; a
solution containing
Select one:
25m CH3OH
the combination of 25m CH3OH and 25m
KCI.
25m KCI.
Explanation:
Antifreeze is the one that reduces the freezing point of a solvent further and will not allow the solvent to freeze.
Among the given options, the correct option is:
25 m CH3OH and 25m KCl.
Since, KOH is a strong electrolyte and dissociates into two ions.
So, the freezing point of solvent decreases further.
Which of the following is an alkaline earth metal?
A Carbon
B aluminum
C magnesium
D silicon
Answer:
Magnesium.
Explanation:
Because it is in group II
Trình bày sự hình thành phân tử CCl4 (lai hoá sp3)
What does the "R-" represent?
A. a halogen
B. a hydroxyl group
C. an alkyl group
D. an oxyacid
URGENT!!
Answer:
general formula RCOX, where R represents an alkyl or aryl organic radical group, CO ... represents a halogen atom such as chlorine ... loss of a hydroxyl group (-OH), viz, acetyl,. CH, CO- ..
The first law of thermodynamics defines chemical energy. defines entropy. is a statement of conservation of energy. provides a criterion for the spontaneity of a reaction.
Answer: The first law of thermodynamics is a statement of conservation of energy.
Explanation:
According to the first law of thermodynamics, heat provided to a system is actually the sum of internal energy and work done by the system or on the system.
Mathematically, [tex]\Delta Q = \Delta U + \Delta W[/tex]
The first law of thermodynamics also means that energy can neither be created nor it can be destroyed. Hence, energy is conserved.
Thus, we can conclude that the first law of thermodynamics is a statement of conservation of energy.
(URGENT!) Which of these graphs best models the waves in the four locations?
(100 points)
i can not understand the question. There seems to be missing info
which selection is an example of an electrolyte
a. potassium iodide in water
b. sucrose in water
c. pentane in octane
d. methanol in water
Answer:
i believe its A, potassium iodide in water
Explanation:
liquid junction potential arise due to?
Answer:
liquid junction potentials
when a cell contains a boundary between two electrolytic solutions of different composition or concentration, a liquid junction potential is developed due to the "diffusion of the various components at characteristic rates in the boundary zone."
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Rank each of the following gases in order of increasing urms assuming equivalent amounts and all gases are at the same temperature and pressure where 1 has the lowest urms and 4 has the highest urms.
a. Gas 1 : H2S
b. Gas: He
c. Gas 3: NF3
d. Gas 4: H2O
The Urms refers to the root mean square speed of the gas. The order of increasing Urms for the gases shown in the question; NF3 < H2S < H2O < He.
What is the Urms?The Urms refers to the root mean square speed of the gas. This is ultimately dependent on the relative molecular mass of the gases when they are maintained at the same temperature.
Now, let us look at the order of increasing Urms for the gases shown in the question; NF3 < H2S < H2O < He.
Learnmore about Urms: https://brainly.com/question/365923
If I have 21 liters of gas held at a pressure of 78 atm and a temperature of 900. K, what will be the volume of the gas if I decrease the pressure to 52 atm and decrease the temperature to 750 K?
SHOW YOUR WORK
Answer:
txyxyc8uviciycuyc
Explanation:
gghvj ucy7cyvyfy
When electrons in a molecule are not found between a pair of atoms but move throughout the molecule, this is called Group of answer choices
Answer:
delocalised electrons
Explanation:
they are called delocalised electrons because that can move freely in the molecule
How many hydrogen atoms are in 3.90 mol of ammonium sulfide?
Answer:
First, the number of ammonium sulfide molecules should be calculated:
N = NA × n,
where NA - the Avogadro number, n - number of moles.
N (ammonium sulfide) = 6.022 × 1023 × 8.5 mol = 51.187 × 1023.
The moelcular formula of ammonium sulfide is (NH4)2S. It means that each molecule contains 8 hydrogen atoms.
As a result, 8.5 mol of (NH4)2S contain:
51.187 × 1023 × 8 = 41 × 1024 hydrogen atoms.
Answer: 41 × 1024 hydrogen atoms
In an exothermic chemical reaction:____.
A. The mass of the products is greater than the mass of the reactants.
B. The mass of the products is less then the mass of the reactants.
C. Heat is released as the reaction proceeds.
D. Heat is absorbed as the reaction proceeds.
Answer:
C
Explanation:
Think of 'exo' as exit and 'thermic' as relating to thermal energy/ heat. Thus, an exothermic release thermal energy as the reaction proceeds.
In an exothermic reaction, the total energy of the products is lesser than that of the reactants and ΔH (change in energy) is less than zero.
When heat is absorbed as the reaction proceeds, the chemical reaction is an endothermic reaction.
Predict the products of below reaction, and whether the solution at equilibrium will be acidic, basic, or neutral.
N2O5 + 3H2O → __________
Answer: The product of the given reaction is [tex]HNO_{3}[/tex] and the solution at equilibrium will be acidic.
Explanation:
When two or more chemical substances react together then it forms new substances and these new substances are called products.
For example, [tex]3N_{2}O_{5} + 3H_{2}O \rightarrow 6HNO_{3}[/tex]
This shows that nitric acid [tex](HNO_{3})[/tex] is the product formed and it is an acidic substance.
Hence, the solution at equilibrium will be acidic in nature.
Thus, we can conclude that the product of the given reaction is [tex]HNO_{3}[/tex] and the solution at equilibrium will be acidic.
Suppose you are using distillation to separate cyclohexane and toluene. The boiling point of cyclohexane is ______ oC and the boiling point of toluene is ______ oC. Therefore, the liquid collected first should be ______
Please put an answer in each box.
Answer: The boiling point of cyclohexane is 81oC and the boiling point of toluene is 111oC. Therefore the liquid collected first should be
CYCLOHEXANE
Explanation:
In chemistry, there are various separation techniques that can be used to separate the components of a mixture and even isolate each of these components. A typical example of such separation techniques is DISTILLATION. This is a method of separation that makes use of different boiling points of liquids in a mixture. A mixture of any number of liquids could be separated as long as they boil at different temperatures. Example include:
--> mixture of cyclohexane (boiling point is 81°C) and toluene (boiling point is 111°C)
--> mixture of alcohol (boiling point is 78°C) and water (boiling point 100°C).
The process involves heating the mixture of liquids until the more volatile liquid ( that is the one with the lower boiling point) changes to vapour. The vapour is cooled by passing it through a condenser and collected in a liquid form known as distillate.
Therefore in the mixture of cyclohexane and toluene, the liquid collected FIRST should be CYCLOHEXANE.
How much cesium (half-life = 2 years) would remain from a 10 g sample after
6 years?
O A. 59
O B. 119
O c. 2 1 2
O D.09
Answer:
The correct answer is A. 59.
Explanation:
The formula for finding the amount of radio active substance that remains after decomposition is A = N(1/2) ^y, where A is the mass remaining, N is the original mass of a radioactive sample and y is the number of half life. In this case, N = 10 g and y = 6/2 = 3. So A is given by 10 x (1/2)^3, which is 10 x 1/2 x1/2 x 1/2 = 1.25 grams.
The speed limit on parts of the German autobahn was once set at 286 kilometers per hour (km/h). Calculate the speed limit in miles per hour (mph).
Answer: 178mph
Explanation:
From the question given, we are informed that the speed limit on parts of the German autobahn was once set at 286 kilometers per hour (km/h). Based on the information, the speed limit in miles per hour will then be:
= 286km/h × 1000m/1km × 1mi/1609m
= 178miles per hour
Therefore, the speed limit is 178mph.
300.0 mL of a 0.335 M solution of NaI is diluted to 700.0 mL. What is the new concentration of the solution?
Answer: The new concentration of the solution is 0.143 M.
Explanation:
Given: [tex]V_{1}[/tex] = 300.0 mL, [tex]M_{1}[/tex] = 0.335 M
[tex]V_{2}[/tex] = 700.0 mL, [tex]M_{2}[/tex] = ?
Formula used is as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}[/tex]
Substitute values into the above formula as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}\\0.335 M \times 300.0 mL = M_{2} \times 700.0 mL\\M_{2} = 0.143 M[/tex]
Thus, we can conclude that the new concentration of the solution is 0.143 M.
Para formar bronce, se mezclan 150g de cobre a 1100°C y 35g de estaño a 560°C. Determine la temperatura final del sistema.
Dato: Ce Cu: 0,093 cal/gºC; Ce Sn: 0,060 cal/gºC
Answer:
[tex]T_F=1029\ºC[/tex]
Explanation:
¡Hola!
En este caso, dada la información, es posible determinar que la temperatura del sistema estará entre 560 °C y 1100 °C, por lo tanto, se hará necesario establecer la suma de la energía del cobre y del estaño como cero:
[tex]Q_{Cu}+Q_{Sn}=0[/tex]
Así, podremos escribir esta ecuación en términos de masas, calores específicos y temperaturas como sigue:
[tex]m_{Cu}C_{Cu}(T_F-T_{Cu})+m_{Sn}C_{Sn}(T_F-T_{Sn})=0[/tex]
Con el fin de resolver para la temperature final:
[tex]T_F=\frac{m_{Cu}C_{Cu}T_{Cu}+m_{Sn}C_{Sn}T_{Sn}}{m_{Cu}C_{Cu}+m_{Sn}C_{Sn}}[/tex]
Así, reemplazamos las variables conocidas como se muestra a continuación:
[tex]T_F=\frac{150g*0.093cal/g\ºC*1100\°C+35g*0.060cal/g\ºC*560\°C}{150g*0.093cal/g\ºC+35g*0.060cal/g\ºC}\\\\T_F=1029\ºC[/tex]
¡Saludos!
i.What are organic fertilizers?
ii.State three advantages of organic fertilizers over inorganic fertilizers.
Answer:
Organic fertilizers are those fertilizers that are not artificially produced but are natural and has carbon in them.
Fertilizers in the broad term are used to provide nutrient to the soil and boost growth of crops.
Some of the advantages of organic fertilizers to inorganic fertilizers are:
They do not make crusts on the soil, unlike inorganic fertilizers.
They help add structure to the soil because of the good water movement into the soil
They are easier on the soil because they feed good microbes.