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]
A sample of brass, which has a specific heat capacity of , is put into a calorimeter (see sketch at right) that contains of water. The temperature of the water starts off at . When the temperature of the water stops changing it's . The pressure remains constant at . Calculate the initial temperature of the brass sample. Be sure your answer is rounded to significant digits.
Answer:
The initial temperature of the brass sample is 90.1°C
Note: The question is incomplete. A similar but complete question is given below :
A 52.9g sample of brass, which has a specific heat capacity of 0.375·J·g−1°C−1, is put into a calorimeter (see sketch at right) that contains 100.0g of water. The temperature of the water starts off at 15.0°C. When the temperature of the water stops changing it's 18.4°C. The pressure remains constant at 1 atm. Calculate the initial temperature of the brass sample. Be sure your answer is rounded to 2 significant digits.
Explanation:
Assuming that the calorimeter is an isolated system and that no heat is lost from the calorimeter. The total heat in the system is the sum of the heat content of the brass and that of water
Total heat lost by the brass = heat gained by the water
The quantity of heat lost or gained, Q = mcΔT
Where m = mass of the substance, c = specific heat capacity of substance, ΔT = temperature change
Heat gained by water is positive while heat lost by brass is negative
mass of brass = 52.9 g, specific heat capacity of brass = 0.375·J·g−1°C−1, ΔT = (18.4 - t °C; where t is the initial temperature), mass of water = 100.0 g, specific heat capacity of water = 4.186 J/g°C, ΔT = = 18.4 - 15.0 = 3.4 °C
Heat lost by brass z= - [ 52.9 × 0.375 × (18.4 - t)] = -365.01 + 19.8375t
Heat gained by water = 100 × 4.186 × 3.4 = 1423.24
Equating heat lost by brass to heat gained by water
-365.01 + 19.8375t = 1423.24
19.8375t = 1423.24 + 365.01
19.8375t = 1788.25
t = 90.1° C
Therefore, the initial temperature of the brass sample is 90.1°C
Identify the options below that are results of adding a catalyst to a chemical system.
The reaction rates are increased.
The reaction quotient is unaffected.
The reaction quotient decreases.
The equilibrium constant is unaffected.
Answer:
The correct options are a, b and d
Explanation:
A catalyst is a substance that increases the rate of a chemical reaction by reducing the activation energy. Le Catelier's principle explains how a substance or an "action" can affect a reaction in equilibrium.
The principle states that when a change is made to the conditions of a reacting system at equilibrium, the position of the equilibrium moves to counteract the change made. These changes are change in temperature, pressure, volume and/or concentration. These changes will either cause the equilibrium to shift forward or backward.
However, the presence of a catalyst DOES NOT affect a chemical equilibrium/equilibrium constant nor does it affect the reaction quotient because the same amount of reactants and products are available just as in uncatalyzed reaction except that the reaction proceeds faster (which does not affect equilibrium).
The rate of reaction is given as the time required by the reactant to convert into the product. The addition of catalyst increases the rate of reaction, while the reaction quotient and the equilibrium remain unaffected.
What is a catalyst?A catalyst is a chemical or compound that adds to the reaction and lowers the activation energy by providing an alternative path to the reaction.
The catalyst takes part in the reaction but did not consume in the chemical reaction.
The equilibrium and the reaction quotient are dependent on the conversion of the reactant to the product. The catalyst is not used in the reaction and thus did not affect the reaction quotient or the equilibrium.
Hence, options A, B, and D are correct for the use of catalysts in the chemical reaction.
Learn more about catalysts, here:
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The N H 2 group makes the molecule an amine. Like alcohols, amines can participate in hydrogen bonding. If the drawn molecule encounters water molecules, there will be (select all that apply): a hydrogen bond between the hydrogen of water and the carbon of the amine. a hydrogen bond between the hydrogen of water and the nitrogen of the amine. a hydrogen bond between the oxygen of water and a hydrogen from the -NH2 group. a hydrogen bond between the oxygen of water and a hydrogen from the -CH3 group. no hydrogen bonds.
Answer:
a hydrogen bond between the hydrogen of water and the nitrogen of the amine
a hydrogen bond between the oxygen of water and a hydrogen from the -NH2 group
Explanation:
A hydrogen bond is formed between molecules in which hydrogen is bonded to a highly electronegative element.
In amines, hydrogen is bonded to nitrogen while in water, hydrogen is bonded to oxygen. Both are highly electronegative elements hence hydrogen bonding is possible between amines and water.
This hydrogen bond may involve;
The hydrogen of water and the nitrogen of the amine
Or
The oxygen of water and a hydrogen from the -NH2 group
Voltages listed in textbooks and handbooks are given as standard cell potentials (voltages). What is meant by a standard cell?
Answer:
Find the definition below.
Explanation:
A standard cell is a group of transistors that have a regular electromotive force flowing through them. They follow either the boolean function or the storage function. A technology library that is made up of a collection of standard cells can be used to facilitate the placement, routing, and synthesis of the Application-specific Integrated Circuit (ASIC).
Electronic Design Automation is an example of an apparatus that implements this functionality.
Many reactions involve a change in hybridization of one or more atoms in the starting material. In this reaction, determine the hybridization of the indicated atoms in the organic starting material, and determine if they have changed hybridization during the reaction.
Answer:
Please find the complete question and its solution file in the attachment.
Explanation:
Which one of the following is an example of a balanced chemical reaction?
a. 8HCl + 2KMnO4 → 3Cl2 + 2MnO2 + 4H2O + 2KCl.
b. 6HCl + 2KMnO4 → 2Cl2 + 2MnO2 + 4H2O + 2KCl.
c. 2HCl + 2KMnO4 → Cl2 + MnO2 + 2H2O + 2KCl.
d. HCl + KMnO4 → Cl2 + MnO2 + H2O + KCl.
e. HCl + KMnO4 → Cl2 + MnO2 + 2H2O + KCl.
Answer:
Option a.
Explanation:
To determine which is a balanced chemical reaction, see the stoichiometry.
Stoichiometry coefficients are the numbers that appear before the compounds. These numbers indicate moles of substance.
Notice that the number of elements must be the same in both sides of the equation.
In this case, option a is the balanced chemical reaction.
8HCl + 2KMnO₄ → 3Cl₂ + 2MnO₂ + 4H₂O + 2KCl
8 moles of HCl react to 2 moles of potassium permanganate in order to produce 2 moles of magnessium dioxide, 3 moles of chlorine, 2 moles of potassium chloride and 4 moles of water.
8 H, 8 Cl, 2 K, 2 Mn and 8 O
The chemical formula for hydrogen chloride is HCl A chemist determined by measurements that moles of hydrogen chloride participate in a chemical reaction. Calculate the mass of hydrogen chloride that participates. Be sure your answer has the correct number of significant digits.
The question is incomplete, the complete question is;
. A chemist determined by measurements that 0.015 moles of hydrogen chloride participate in a chemical reaction. Calculate the mass of hydrogen chloride that participates Round your answer to 2 significant digits. x S. ?
Answer:
0.54 g
Explanation:
Recall that;
Number of moles = mass/molar mass
Molar mass of HCl =36.5 g/mol
Mass= number of moles × molar mass
Mass= 0.015 moles × 36 g/mol
Mass= 0.54 g
All of the orbitals in the 3d subshell have a principal quantum number value of 3, an angular momentum quantum number of:_____.
Answer:
According to the four quantum numbers; magnetic quantum number is the same as angular momentum quantum number. so the answer is 5
Explanation:
for d subshell angular momentum "d" is assigned a value of : m= 2(range from negative to positive i.e, -2 to 2) so we have [ -2, -1 ,0, 1 , 2] which concludes to 5.
The blank is the accepted form of gathering and reporting information within the science community.
Answer:
Scientific method.
Explanation:
Scientific method is the way taken to acquire scientific knowledge. It includes experiments, statistical analysis of existing data, and all kinds of observations of the world around us, while theoretical research is based on deriving certain theories about the world from basic principles, in a mathematical or logical way. The scientific method applies to both types of research, and emphasizes that scientific research is objective, that it can be verified by other scientists, and that knowledge is not acquired without context, but in a way that leads to a greater understanding of previous research and the world. we live in. To contribute to this, researchers are expected to clearly record both their findings and the methods they use to arrive at the results.
A reaction produces 3.0 mol of gas, which occupies 1.46 L. What is the volume of the product when 4.1 mol are produced at constant temperature and pressure?
Answer:
1.99 L
Explanation:
Given that,
A reaction produces 3.0 mol of gas, which occupies 1.46 L.
We need to find the volume of the product when 4.1 mol are produced at constant temperature and pressure.
We know that,
PV = nRT
i.e.
[tex]V\propto n\\\\\dfrac{V_1}{V_2}=\dfrac{n_1}{n_2}\\\\V_2=\dfrac{V_1n_2}{n_1}\\\\V_2=\dfrac{1.46\times 4.1}{3}\\\\V_2=1.99\ L[/tex]
So, the new volume is 1.99 L.
Which group has one valence electron
Answer:
Alkaline earth metals or akali metals
a sample of copper was heated at 275.1 C and placed into 272 g of water at 21.0 C. The temperature of the water rose at 29.7 C. How many grams of copper were in the sample
Answer:
104.8 g
Explanation:
From the question given above, the following data were obtained:
Initial temperature of copper (T꜀) = 275.1 °C
Mass of water (Mᵥᵥ) = 272 g
Initial temperature of water (Tᵥᵥ) = 21 °C
Equilibrium temperature (Tₑ) = 29.7 °C
Mass of copper (M꜀) =?
NOTE:
Specific heat capacity of copper (C꜀) = 0.385 J/gºC
Specific heat capacity of water (Cᵥᵥ) = 4.184 J/gºC
Finally, we shall determine the mass of the copper in the sample. This can be obtained as follow:
Heat loss by copper = Heat gained by water
M꜀C꜀(T꜀ – Tₑ) = MᵥᵥCᵥᵥ(Tₑ – Tᵥᵥ)
M꜀ × 0.385 (275.1 – 29.7) = 272 × 4.184(29.7 – 21)
M꜀ × 0.385 × 245.4 = 1138.048 × 8.7
M꜀ × 94.479 = 9901.0176
Divide both side by 94.479
M꜀ = 9901.0176 / 94.479
M꜀ = 104.8 g
Thus, the mass of the copper in the sample is 104.8 g
How many carbon atoms are there in 15 lbs of sugar, C12H22O11?
Answer:
A molecule of sucrose (C12H22O11) has 12 carbon atoms, 22 hydrogen atoms and 11 oxygen atoms.
Explanation:
if this does not help let me know :)
There are 1.4376 × 10²⁶ carbon atoms in 15 lbs of sugar (C12H22O11).
From the given information,
Using the standard conversion method;
1 lbs = 453.592 gram
∴
15 lbs = (453.592 gram × 15 lbs/1 lbs)
= 6803.88 grams
Now, we will need to determine the molar mass of the sugar compound C12H22O11.
Molar mass of C12H22O11 = (12 × 12) +(1 × 22) + (16 × 11)
Molar mass of C12H22O11 = 144 + 22 + 176
Molar mass of C12H22O11 = 342 g/mol
Using the relation:
[tex]\mathbf{Number \ of \ moles = \dfrac{mass}{molar \ mass}}[/tex]
Number of moles = [tex]\dfrac{6803.88 }{ 342}[/tex]
Number of moles of C12H22O11 = 19.894 moles
Since we've known the number of moles present in C12H22O11, the next thing to do is determine the number of molecules of sugar by using Avogadro's constant:
i.e.
number of moles of sugar = [tex]19.894 moles \times \dfrac{6.023 \times 10^{23}}{mol}[/tex]
= 1.198 × 10²⁵ molecules of C12H22O11
Now to determine the number of carbon atoms in 15 lbs, we have:
= number of carbon atoms × amount of molecules
= 12 × 1.198 × 10²⁵ carbon atoms
= 1.4376 × 10²⁶ carbon atoms
Therefore, we can conclude that there are 1.4376 × 10²⁶ carbon atoms present in 15 lbs of sugar, C12H22O11
Learn more about atoms here:
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Identify the most oxidized compound. Group of answer choices CH3CH2CHO CH3CH2CH3 CH3CH2CH2OH CH3CH2OCH3 CH3CH2COOH
Answer:
Huh!?
Explanation:
explain me please
What is the mass of 2.30x10^22 formula units of NaOH (molar mass =40.0g/mol)
Answer:
643(%=:(¥75 )(:7$"8"),"7$"()9_/"¥?:
A sample of 10.6 g of KNO3 was dissolved in 251.0 g of water at 25 oC in a calorimeter. The final temperature of the solution was 21.5 oC. What is the molar heat of solution of KNO3
Answer:
36.55kJ/mol
Explanation:
The heat of solution is the change in heat when the KNO3 dissolves in water:
KNO3(aq) → K+(aq) + NO3-(aq)
As the temperature decreases, the reaction is endothermic and the molar heat of solution is positive.
To solve the molar heat we need to find the moles of KNO3 dissolved and the change in heat as follows:
Moles KNO3 -Molar mass: 101.1032g/mol-
10.6g * (1mol/101.1032g) = 0.1048 moles KNO3
Change in heat:
q = m*S*ΔT
Where q is heat in J,
m is the mass of the solution: 10.6g + 251.0g = 261.6g
S is specififc heat of solution: 4.184J/g°C -Assuming is the same than pure water-
And ΔT is change in temperature: 25°C - 21.5°C = 3.5°C
q = 261.6g*4.184J/g°C*3.5°C
q = 3830.87J
Molar heat of solution:
3830.87J/0.1048 moles KNO3 =
36554J/mol =
36.55kJ/mol
The metal tantalum becomes superconducting at temperatures below 4.483 K. Calculate the temperature at which tantalum becomes superconducting in degrees Celsius.
Answer:
The correct answer is "-268.667°C".
Explanation:
Given:
Temperature,
= 4.483 K (below)
Now,
The formula of temperature conversion will be:
⇒ [tex]T(^{\circ} C)=T(K)-273.15[/tex]
By putting the values, we get
⇒ [tex]=4.483-273.15[/tex]
⇒ [tex]=-268.667^{\circ} C[/tex]
Thus the above is the correct answer.
4. What is the percent yield of a reaction that produces 12.5 g CF2Cl2 from 32.9 g of CCl4 and excess HF
Answer:
Percent yield = 48.3%
Explanation:
The reaction is:
CCl₄ + 2HF → CF₂Cl₂ + 2HCl
1 mol of CCl₄ reacts with 2 moles of hydrofluoric acid in order to produce 1 mol of CF₂Cl₂ and 2 moles of hydrogen chloride.
HF is in excess, so the limiting reagent is the CCl₄.
We convert mass to moles:
32.9 g . 1mol / 153.8g = 0.214 moles
Ratio is 1:1. In conclussion: 0.0813 moles of CCl₄ can produce 0.0813 moles of CF₂Cl₂. We convert moles to mass, to determine the theoretical yield:
0.214 mol . 120.91g /mol = 25.8 g
Percent yield = (Yield produced /Theoretical yield) . 100
Percent yield = (12.5 g/ 25.8g) . 100 = 48.3%
Consider the balanced chemical equation below.
3 A ⟶ C + 4 D
How many moles of C would be produced if 7 moles of A were used?
Answer:
2.33 mol C
Explanation:
Step 1: Write the balanced generic chemical equation
3 A ⟶ C + 4 D
Step 2: Establish the appropriate molar ratio
According to the balanced equation, the molar ratio of A to C is 3:1.
Step 3: Calculate the number of moles of C produced from 7 moles of A
We will use the previously established molar ratio.
7 mol A × 1 mol C/3 mol A = 2.33 mol C
The element least likely to obey the octet rule in forming chemical bonds is Group of answer choices oxygen. carbon. nitrogen. neon. fluorine.
Answer:
neon
Explanation:
The octet rule states that atoms of elements are stable when they possess 8 electrons on their outermost shell.
Hence, atoms of elements participate in chemical reactions in order to attain this octet structure (eight electrons in the outermost shell).
Neon is a noble gas and already has eight electrons in its outermost shell. Hence, neon is least likely to obey the octet rule.
Methanoic acid is the simplest carboxylic acid molecule. It has one carbon atom. Draw the structural model for methanoic acid (using C and H).
ANSWER IS ABOVE
THE METHANOIC ACID
What is the law of multiple proportions?
A. The proportion of elements to compounds is constant.
B. All elements are found in equal proportions in nature.
C. Different compounds may contain the same elements but may have different ratios of those elements.
D. All compounds contain the same elements in the same proportions.
Answer:
a. the proportion of elements to compounds is constant.
Indicate how the concentration of each species in the chemical equation will change to reestablish equilibrium after reactant or product is added.
2CO(g) + O2(g) ⇌ 2CO2
Answer:
Indicate how the concentration of each species in the chemical equation will change to reestablish equilibrium after reactant or product is added.
[tex]2CO(g) + O2(g) <=> 2CO2[/tex]
Explanation:
When the reactants concentration increases, then the equilibrium will shift towards products and when the concentration of products increases, then equilibrium will shift towards reactants.
So, increases in concentration of carbon monoxide (CO) shifts the equilibrium to favor the formation of carbondioxide.
Similarly increase in concentration of oxygen also favor the formation of product carbon dioxide.
Increase in concentration of CO2 favors the formation of CO and O2.
Decrease in product concentration also favors the formation of product.
Decrease in reactant concentration favors the formation of reactants only.
Na2CO3 reacts with dil.HCl to produce NaCl, H2O and CO2. If 21.2 g of pure Na2CO3 are added in a solution containing 21.9g HCl , a. Find the limiting reagent. (2) b. Calculate the number of moles of excess reagent left over.(2) c. Calculate the number of molecules of H2O formed.(1) d. Calculate volume of CO2 gas produced at 270C and 760mm Hg pressure.(2) e. Write significance of limiting reagent
Answer:
See explanation
Explanation:
Equation of the reaction;
Na2CO3(aq) + 2HCl(aq) -------> 2NaCl(aq) + H2O(l) + CO2(g)
Number of moles of Na2CO3 = 21.2g/106g/mol = 0.2 moles Na2CO3
Number of moles of HCl = 21.9g/36.5g/mol = 0.6 moles of HCl
1 mole of Na2CO3 reacts with 2 moles of HCl
0.2 moles of Na2CO3 reacts with 0.2 × 2/1 = 0.4 moles of HCl
Hence Na2CO3 is the limiting reactant
Since there is 0.6 moles of HCl present, the number of moles of excess reagent=
0.6 moles - 0.4 moles = 0.2 moles of HCl
1 mole of Na2CO3 forms 1 mole of water
0.2 moles of Na2CO3 forms 0.2 moles of water
Number of molecules of water formed = 0.2 moles × 6.02 × 10^23 = 1.2 × 10^23 molecules of water
1 mole of Na2CO3 yields 1 mole of CO2
0.2 moles of Na2CO3 yields 0.2 moles of CO2
1 mole of CO2 occupies 22.4 L
0.2 moles of CO2 occupies 0.2 × 22.4 = 4.48 L at STP
Hence;
V1=4.48 L
T1 = 273 K
P1= 760 mmHg
T2 = 27°C + 273 = 300 K
P2 = 760 mmHg
V2 =
P1V1/T1 = P2V2/T2
P1V1T2 = P2V2T1
V2 = P1V1T2/P2T1
V2 = 760 × 4.48 × 300/760 × 273
V2= 4.9 L
The limiting reactant is the reactant that determines the amount of product formed in a reaction. When the limiting reactant is exhausted, the reaction stops.
Ice and water constitute a system:
A Chemically heterogeneous and physically heterogeneous
B Chemically homogeneous and physically heterogeneous
C Chemically homogeneous and physically homogeneous
D Chemically heterogeneous and physically homogeneous
E None of the above
Answer:
B
Explanation:
It's the same substance but in different states.
HETEROGENEOUS mixtures contain substances that are
not uniform in composition. The parts in the mixture can be separated by physical means.
What is the name of this molecule?
Explanation:
here is your answer
hope this will help you
When we react a weak acid with a strong base of equal amounts and concentration, the component of the reaction that will have the greatest effect on the pH of the solution is: Select the correct answer below:_________
a. the reactant acid
b. the reactant base
c. the conjugate acid of the strong base
d. the conjugate base of the weak acid
Answer:
d. the conjugate base of the weak acid
Explanation:
The strong base (BOH) is completely dissociated in water:
BOH → B⁺ + OH⁻
The resulting conjugate acid (OH⁻) is a weak acid, so it remains in solution as OH⁻ ions.
By other hand, the weak acid (HA) is only slightly dissociated in water:
HA ⇄ H⁺ + A⁻
The resulting conjugate base (A⁻) is a weak base. Thus, it reacts with H⁺ ions from water to form HA, increasing the concentration of OH⁻ ions in the solution.
Therefore, the resulting solution will have a pH > 7 (basic).
What is the molecular formula of the structure below?
Picture is attached pls help I’ll mark as brainliest for the right answer
Answer:
C₆H₆
Explanation:
Each border of the figure represents 1 atom of carbon. We have 6 borders = 6 atoms of carbon.
Each atom of carbon form 4 bonds. All the carbons are doing a double bond and a single bond with other carbons. That means are bonded 3 times. The other bond (That is not represented in the figure. See the image) comes from hydrogens. As we have 6 carbons that are bonded each 1 with one hydrogen. There are six hydrogens and the molecular formula is:
C₆H₆This structure is: Benzene
The largest population that an environment can support is called _____.
A) birth capacity
B) death factor
C)limiting factor
D) carrying capacity
Answer:
D) caring capacity
Explanation:
The largest population that an environment can support is called its carrying capacity.hope it helps.stay safe healthy and happy.Answer:
D)
Explanation:
The largest population that an environment can support is by definition a carrying capacity
Which statement is true about how scientists draw conclusions from data?
A. Scientists do not allow others to make conclusions about their data.
B. Teams of scientists never share their data to help other teams draw conclusions.
C. Any two scientists will always come to the same conclusion about a data set.
D. Two scientists may have different underlying assumptions that lead them to different conclusions about the same data.
Answer:
D. Two scientists may have different underlying assumptions that lead them to different conclusions about the same thing.
Explanation:
It's all about how a person analyzes data. Some do it mathmatically while others do it logically. By doing it different ways, you may still come to the same conclusion, despite working at the problem in a different way.