The literature values listed for the unknowns in this assignment are from either the Merck Index or the CRC Handbook, the two most used reference handbooks. However, the values tend to vary slightly across literature sources and sometimes the temperatures are given as ranges. Give at least one reason for the variations in these reported temperatures.
In general, the boiling points of compounds increase down a group in the periodic table. The melting points and boiling points for the hydrogen compounds of group 6A elements are in the table below.
Melting point (0C) Boiling point (oC)
H2O 0.0 100.0
H2S -82.0 -60.0
H2Se -65.7 -41.2
H2Te -49.0 -2.2
Answer:
See explanation
Explanation:
One of the important trends in the periodic table is electronegativity. Electro negativity decreases down the group and increases across the period. This trend has important consequences on the observed properties of the compounds of elements in a particular group in the periodic table.
As we move down in group 6A, the electro negativity of the elements elements the group decrease and as such, the magnitude of intermolecular hydrogen bonding between the molecules also decrease accordingly. Hydrogen bonds occur between
molecules of a substance when hydrogen is covalently bonded to an electronegative element. Hydrogen bonding is responsible for the high melting and boiling points of small molecules such as water which contain the highly electronegative oxygen atom.
So, as we move down the group there is lesser intermolecular hydrogen bonding between the hydride molecules of group 6A elements resulting in the observed trend in melting and boiling points of the hydrides.
The weaker hydrogen bonds that occurbetween molecules of group 6A hydrides lead to a steady decrease in melting and boiling points of the hydrides of group 6A elements as we move down the group.
What would happen to the pressure of a closed sample of gas whose temperature increased while its volume decreased? Explain your reasoning in terms of the kinetic molecular theory of gases.
Answer:
As the temperature increases, the average kinetic energy increases as does the velocity of the gas particles hitting the walls of the container. The force exerted by the particles per unit of area on the container is the pressure, so as the temperature increases the pressure must also increase.
I hope this will help you if not soo sorry :)
Which of the following aqueous solutions are good buffer systems?
a. 0.34 M calcium iodide + 0.22 M sodium iodide.
b. 0.27 M ammonia + 0.38 M ammonium nitrate.
c. 0.27 M nitric acid + 0.18 M sodium nitrate.
d. 0.18 M hydrofluoric acid + 0.14 M hydroiodic acid.
e. 0.14 M calcium hydroxide + 0.28 M calcium chloride.
Answer:
b. 0.27 M ammonia + 0.38 M ammonium nitrate.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to bear to mind the fact that buffest must be prepared by using either of the following pairs:
weak acid/conjugate base
weak base/conjugate acid
So that the pH might be set constant. In such a way, since a. shows two salts, c. a strong acid with a neutral base, d, shows two acids and e. a strong base with a neutral base, we infer the correct buffer is b. 0.27 M ammonia + 0.38 M ammonium nitrate because it has a weak base (ammonia) and its conjugate acid, ammonium.
Regards!
A mixture of coarse sand and sugar is 45.0 percent sand by mass. 120.0 grams (g) of the mixture is placed in a fine-mesh cloth bag and dunked repeatedly in Lake Michigan. After drying, the mass of the contents of the bag equals: ________.
A. 66.0 g
B. 120.0 g
C. 65.0 g
D. 72.00 g
E. 54.0 g
Answer:
Option E
Explanation:
From the question we are told that:
Amount of sand in percentage [tex]s_p=45%[/tex]
Sample size[tex]n=120g[/tex]
Note:After being dumped in the river repeatedly the sugar melts away leaving behind the insoluble sand
Generally the equation for Amount of sand content is mathematically given by
[tex]X=n*s_p[/tex]
[tex]X=120*\frac{45}{100}[/tex]
[tex]X=54g[/tex]
Therefore
After drying, the mass of the contents of the bag equals
[tex]X=54g[/tex]
Option E
A solution has a [H3O+] of 1 × 10−5 M. What is the [OH−] of the solution?
A) 9 M
B) 14 M
C) 1 x 10^{-9}
D) 1 x 10^{-14}
Why is the reaction SO2 + H2O → H2SO2 not balanced?
There are more oxygen atoms in the reactants while there are less oxygen atoms in the product.
Both sides of the equation is supposed to be balanced for a balanced equation. If any one of them isn't balanced, the equation remains unbalanced.
The main reason why the reaction above can not be balanced is:
This chemical reaction SO2 + H2O -> H2SO2 is not correctly written.
It must be: SO2 + H2O -> H2SO3
hope this helps....
Arrange the forms of electromagnetic radiation in order of decreasing energy (from highest energy to lowest energy). You are currently in a ranking module. Turn off browse mode or quick nav, Tab to move, Space or Enter to pick up, Tab to move items between bins, Arrow Keys to change the order of items, Space or Enter to drop.
highest energy lowest energy
radio waves
x rays
gamma rays
infrared
microwaves
ultraviolet
visible
Answer:
gamma rays > X-rays > ultraviolet radiation > visible light > infrared > radio waves.
Explanation:
Electromagnetic waves are those waves that require no material medium for propagation. They can travel through space and they all move at the speed of light.
Electromagnetic waves are composed of both electric and magnetic fields which are mutually at right angles to each other.
The order of decreasing energy of electromagnetic waves is;
gamma rays > X-rays > ultraviolet radiation > visible light > infrared > radio waves.
12.0: A
Mention three body fluids that are alkaline in nature
5 compounds that has electrovalent and covalent bond
Answer:
electrovalent
NaCl
Lithium Carbonate
ammonium phosphate
aluminium floride
potassium hydride
covalent
methane
benzene
carbon iv oxide
hydro flouride
hydro chloride
A molecular compound has the following empirical formula: CH2O. The molar mass of the empirical formula is g. Write your answer using 3 significant figures. If the molar mass of the molecular compound is 180.0 g/mol, write the molecular formula of the compound.
Answer:
Empirical formula has a molar mass of 30.01g/mol and molecular formula is C₆H₁₂O₆
Explanation:
Molar mass of a molecule is the sum of the molar mass of each atom. In CH2O we have:
1C = 1*12.01g/mol = 12.01g/mol
2H = 2*1g/mol = 2g/mol
1O = 1*16g/mol = 16g/mol
Empirical formula of CH2O is:
12.01g/mol + 2g/mol + 16g/mol = 30.01g/mol
As the molecular compound has a molar mass of 180.0g/mol the molecular formula is:
180.0g/mol / 30.01g/mol = 6 times the empirical formula. That is:
C₆H₁₂O₆The three parts of quality assurance are determining use objectives, setting specifications, and assessment of results. Classify the actions taken during quality assurance by the part of quality assurance in which they should be taken.
a. Document procedures and keep suitable records.
b. Use quality control samples to monitor performance.
c. Compare data and results with specifications.
d. Consider the accuracy and precision needed.
e. Determine the sampling requirements.
f. Follow standard operating procedures.
The actions taken during quality assurance by the part of quality assurance in which they should be taken is to document procedures and keep suitable records. The correct option is a.
What is quality assurance?Quality assurance is checking the quality of objects and services. They are assured in the companies and factories and other places to check the quality of the products.
The different type of quality assurance is: There are different types of quality assurance.
control.acceptance sampling. control charts.product quality control.They work in the set quality and set requirements. They maintain the quality and develop those sets. Furthermore, they manage waste and quality.
Thus, the correct option is a. Document procedures and keep suitable records.
To learn more about quality assurance, refer to the link:
https://brainly.com/question/13164793
#SPJ2
Consider the following reaction at 298 K.
2 SO2(g) + O2(g) → 2 SO3(g)
An equilibrium mixture contains O2(g) and SO3(g) at partial pressures of 0.43 atm and 2.6 atm, respectively. Using data from Appendix 4, determine the equilibrium partial pressure of SO2 in the mixture.
______atm.
Answer and Explanation:
The reaction is in the gas phase, so the equilibrium constant is expressed in terms of the partial pressures (P) of the products and reactants, as follows:
[tex]Kp = \frac{P^{2}_{SO_{3} } }{P_{SO_{2}} ^{2}P_{O_{2}} }[/tex]
We have the following data:
P(SO₃) = 2.6 atm
P(O₂) = 0.43 atm
We need Kp for this reaction. We can assume that in Appendix 4 we found that Kp = 7 x 10²⁴.
Then, we introduce the data in the equilibrium constant expression to calculate the partial pressure f SO₂ (PSO₂), as follows:
[tex]P_{SO_{2} } = \sqrt{\frac{P_{SO_{3} } ^{2} }{Kp P_{O_{2} } } } = \sqrt{\frac{(2.6 atm)^{2} }{(7 x 10^{24)}(0.43 atm) } } = 1.5 x 10^{-12} atm[/tex]
Therefore, the partial pressure of SO₂ is 1.5 x 10⁻¹² atm (for the given Kp).
Consider the following events that take place when rip currents occur.
A. Waves travel to the beach.
B. Waves are trapped by the sandbars.
C. Waves reach the shore and go back to the ocean.
D. Waves speed up and flow between the sandbars.
E. Waves are broken by the sandbars.
Which list shows the order of events in the production of rip currents?
For each molecule, specify the polarity of the bonds and the overall polarity of the molecule.
a. BeCl2
b. H2O
c. O3
heating, the particle _______________ increases as more __________ __________ is added
Answer: what are the choices?!.
Explanation:
A crop is sprayed with a pesticide to prevent infestation and damage from insects. However, the next season the same pesticide fails to prevent the insects from damaging the crop. Why
Answer:
Farmers spray to mitigate crop damage caused by pests. A pest is any biological organism, including weeds, pathogens, and arthropods, that interferes with the production of crops affecting quality and/or yield. ... Pesticides work in many different ways by affecting their target, whether it be a weed, pest, or disease.
Explanation:
this is my answer❤︎
How many moles of water are produced if 3.30 moles of N20 is
produced? NH4NO3 --> N20 + 2 H2O (mole to mole conversion) 1 step
Answer:
The netto reaction equation is:
2 OH- + 2H+ = 2 H2O
So the answer is 2 moles.
What mass of octane (in g) is required to produce 8210 kJ of heat?
Answer:
184.8 g
Explanation:
Step 1: Write the balanced thermochemical equation
C₈H₁₈(l) + 25/2 O₂(g) ⇒ 8 CO₂(g) + 9 H₂O(g) ΔH°rxn = -5074.1 kJ
Step 2: Calculate the moles of octane required to produce 8210 kJ of heat
According to the thermochemical equation, 5074.1 kJ of heat are released per mole of octane consumed.
-8210 kJ × 1 mol C₈H₁₈/(-5074.1 kJ) = 1.618 mol
Step 3: Calculate the mass corresponding to 1.618 moles of octane
The molar mass of C₈H₁₈ is 114.23 g/mol.
1.618 mol × 114.23 g/mol = 184.8 g
1mol produces=5074.1KJ heat .
Moles produce 8210 KJ heat :-
8210/5074.1=1.62molMolar mass of Octane :-
8(12)+18=96+18=114g/molMass of Octane=
1.62(114)=184.7gUsing the following equation how many grams of water you would get from 886 g of glucose:
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
Answer:
531.6g
Explanation:
Total moles of glucose in this case is: 886/180= 4.922 (mole)
For every 1 mole glucose we get 6 mole water
-> Mole of water is: 4.922 * 6= 29.533 (mole)
weight of water is 18. Therefore, total weight of water that we will have from 886g of glucose are: 25.933*18= 531.6g
What is the pCu of the resulting solution if 20.00 mL of 0.08 M EDTA (H4Y) is added to 15.00 mL of 0.10 M CuSO4 and buffered at pH 10? The Kf’ for complex CuY2- is 2.21 x 1018
Answer:
The answer is "5.4".
Explanation:
[tex]BoH + HCL =BCL +H_2o \\\\At eq \\\\N_1V_1=N_2V_2 \\\\v_2=20 \ ml\\\\[BCL]=\frac{20 \times 0.08}{20+20}=0.04\\\\pH = \frac{1}{2} [pkw - pk_b - \log e]\\\\pk_b = 2 pH - Pkw + \Log C\\\\pK_b=5.4[/tex]
a. Compound A and compound B are constitutional isomers with molecular formula C3H7Cl. When compound A is treated with sodium methoxide, a substitution reaction predominates. When compound B is treated with sodium methoxide, an elimination rection predominates. Propose structures A and B.
b. An unknown compound with molecular formula C6H13Cl is treated with sodium ethoxide to produce 2,3-dimethyl-2-butene as the major product. Identify the structure of the unknown compound.
Answer:
história phkfk
Explanation:
guiooupigjdytrss
list some applications of chemistry in your dail life
Chemistry and chemical reactions are not just limited to the laboratories but also the world around you.
Chemistry in Food Production:
Plants produce food for themselves through photosynthesis; which is a complex chemical reaction in itself. The chemical reaction that takes place in photosynthesis is the most common and vital chemical reaction.
6 CO2 + 6 H2O + light → C 6H12O6 + 6 O2
Chemistry in Hygiene:
Right before you consume your food, you make it a point to wash your hands with soap. Isn’t it? The cleaning action of soap is based on its ability to act as an emulsifying agent. Soaps are fatty acids salts of sodium or potassium; produced by a chemical reaction called saponification. Soaps interact with the grease or oil molecule, which, in turn, results in a cleaner surface.
The Chemistry of an Onion:
Ever wondered why you shed tears while chopping an onion? This also happens because of the underlying chemistry concepts. As soon as you slice an onion, sulfenic acid is formed from amino acid sulfoxides. Sulfenic acid is responsible for the volatile gas, propanethiol S-oxide, that stimulates the production of tears in the eyes.
Chemistry in Baking:
Who does not like to eat fluffy freshly baked bread? Baking soda is an efficient leavening agent. The addition of baking soda to food items before cooking leads to the production of carbon dioxide (CO2); which causes the foods to rise. This whole process of rising of baked good is called chemical leavening.
Chemistry in Food Preservatives:
In case you ever read the ingredients on the bottle of ketchup, jams or pickles, you might be surprised to see a never-ending list of chemicals. What are they? These chemicals are called food preservatives; which delay the growth of microorganisms in foods. The chemical food preservatives not only prohibit the growth of bacteria, virus, fungi but also hinder the oxidation of fats, which is responsible for making the foods rancid. The most common chemical food preservatives are sodium benzoate, sorbic acid, potassium sorbate, calcium sorbate, sodium sorbate, propionic acid, and the salts of nitrous acid.
Chemistry in Digestion
The moment you put food in your mouth, a number of different chemical reactions start in your digestive tract. Saliva contains the enzyme amylase, which is responsible for breaking down carbohydrates, the stomach starts producing hydrochloric acid, the liver releases bile and the list of compounds released during digestion goes on. How do they work? All these enzymes undergo chemical reactions so that proper digestion, as well as assimilation of the food, occurs.
The Working of a Sunscreen
Before going out on a sunny day, you make it a point to wear sunscreen. Even the principle, behind the working of a sunscreen, has a chemistry background. The sunscreen uses a combination of organic and inorganic compounds to act as a filter for incoming ultraviolet rays. Sunblocks, on the other hand, scatter away UV light; so that it is unable to penetrate deep into the skin. Sunblocks contain complex chemical compounds like zinc oxide or titanium oxide, which prevent the UV rays to invade deeper into the skin.
Chemistry in Rust Formation
With time, your iron instruments start developing an orange-brown flaky coating called rust. The rusting of iron is a type of oxidation reaction. The atoms in the metal iron undergo oxidation and reduction; causing rusting. The formation of verdigris on copper and the tarnishing of silver are also the other everyday examples of chemical reactions. The chemical equation underlying rusting is:
Fe + O2 + H2O → Fe2O3. XH2O
Hope it helps.
A solution of acetic acid that has a concentration of 0.10 moles per liter has a pH of 2.87. What is the likely pH of a 0.10 mole per liter solution of the conjugate base sodium acetate?
A. 8.97
B. 1.00
C. 2.87
D. 4.74
E. 13.00
Answer: The correct option is A) 8.97
Explanation:
To calculate the [tex]K_b[/tex] of a reaction, we use the equation:
[tex]K_a\times K_b=10^{-14}[/tex]
where,
[tex]K_a[/tex] = acid dissociation constant of acetic acid = [tex]1.86\times 10^{-5}[/tex]
[tex]K_b[/tex] = base dissociation constant
Putting values in above equation, we get:
[tex](1.86\times 10^{-5})\times K_b=10^{-14}\\\\K_b=\frac{10^{-14}}{1.86\times 10^{-5}}=5.37\times 10^{-10}[/tex]
To calculate the hydroxide ion concentration of conjugate base, we use the equation:
[tex][OH^-]=\sqrt{K_b\times \text{[Conjugate base]}}[/tex]
where,
[Conjugate base] = 0.10 M
Putting values in above equation, we get:
[tex][OH^-]=\sqrt{(5.37\times 10^{-10})\times 0.1}[/tex]
[tex][OH^-]=7.33\times 10^{-6}[/tex]
To calculate the pOH of the solution, we use the equation:
[tex]pOH=-\log [OH^-][/tex]
[tex]pOH=-\log (7.33\times 10^{-6})[/tex]
[tex]pOH=5.03[/tex]
To calculate the pH of the solution, we use the equation:
pH + pOH = 14
pH + 5.03 = 14
pH = (14 - 5.03) = 8.97
Hence, the correct option is A) 8.97
A buffer solution contains 0.472 M hydrocyanic acid and 0.342 M sodium cyanide. If 0.0194 moles of sodium hydroxide are added to 150 mL of this buffer, what is the pH of the resulting solution
Answer:
pH = 9.54.
Explanation:
Hello there!
In this case, since this is an acidic buffer due to the hydrocyanic acid, it will be firstly necessary for us to calculate the moles of both acid and conjugate base in 150 mL given their concentrations:
[tex]n_{acid}=0.472mol/L*0.150L=0.0708mol\\\\n_{base}=0.342mol/L*0.150L=0.0513mol[/tex]
Next, since the effect of adding NaOH, consume the acid and produce more base, we subtract 0.0194 moles from 0.0708 mol and add 0.0194 to 0.0513 mol for us to calculate the new moles:
[tex]n_{acid}^{new}=0.0708mol-0.0194mol=0.0514mol\\\\n_{base}^{new}=0.0513mol+0.0194mol=0.0707mol[/tex]
Thus, since the pKa of hydrocyanic acid is 9.40, we therefore use the Henderson-Hasselbach equation to calculate the pH of the resulting solution for the same volume:
[tex]pH=9.40+log(\frac{0.0707mol}{0.0514mol} )\\\\pH=9.54[/tex]
Which increase make sense since we added some strong base.
Regards!
Rita determined the experimental van 't Hoff factor, i, for KCl to be 1.9 which is less than the theoretical value of 2. Select the option that best explains the difference between the theoretical and experimental i.a) The difference is due to the ion-pairing effect which effectively reduces the number of solute particles present in the solution.b) The difference is due to the ion-pairing effect which effectively increases the number of solute particles present in the solution correct amount of KCl that will give better agreement between the experimental and theoretical results.c) Rita did not freeze the entire sample.
Answer:
The difference is due to the ion-pairing effect which effectively reduces the number of solute particles present in the solution.
Explanation:
Colligative properties are those properties that depend on the amount of solute present. Such properties include; boiling point elevation, freezing point depression etc.
Ion pairing causes the Van't Hoff factor to deviate from whole numbers. Ion pairing effect generally reduces the number of solute particles in solution thereby decreasing the experimental value of the Van't Hoff factor (i).
Hence, the reason why Rita determined the Van't Hoff factor as 1.9 and not the theoretical value of 2 is because of on-pairing effect which effectively reduces the number of solute particles present in the solution.
The difference between the theoretical and experimental is A. The difference is due to the ion-pairing effect which effectively reduces the number of solute particles present in the solution.
Colligative propertiesIt should be noted that colligative properties simply means the properties that depend on the amount of solute present.
The ion pairing causes the Van't Hoff factor to deviate from whole numbers. Therefore, they caused the difference between the theoretical and experimental values.
Learn more about ion on:
https://brainly.com/question/11638999
A calorimeter measures the heat involved in reactions or other processes by measuring the temperature change of the materials ________ the process The calorimeter is_______ to prevent transfer of heat to outside the device A calorimeter measures the heat involved in reactions or other processes by measuring the temperature change 01 the process the materials _______. _______ produced by The calorimetelinvolved in surrounding to prevent transfer of heat to outside the device. A calorimeter measures the heat involved in reactions or other processes by measuring the temperature change of the materials _______ the process to prevent transfer of heat to outside the device. The calorimeter is _____ _______Insulated conductive left open V A calorimeter measures the heat involved in reactions or other processes by measuring the temperature change _______ the materials ______ SS moles mass heat The calorimeter is _______comprevent transfer of heat to outside the device of A calorimeter measures the heat involved in reactions or other processes by measuring the temperature chang- ______ the materials _______ the process mass gain enthalpy change temperature change The calorimeter is ________... to prevent transfer of heat to outside the device
Complete Question:
A calorimeter measures the heat involved in reactions or other processes by measuring the ______ of the materials _____ the process. The calorimeter is _______ to prevent transfer of heat to outside the device.
Answer:
Temperature; surrounding; insulated.
Explanation:
A calorimeter can be defined as a scientific instrument or device designed and developed for measuring the heat involved in reactions or other processes, especially by taking the measurement of the temperature of the materials surrounding the process.
Basically, a calorimeter is insulated using materials with very high level of resistivity so as to prevent heat transfer to the outside of the device (calorimeter). Some of the components that make up a simple calorimeter are thermometer, an interior styrofoam cup, an exterior styrofoam cup, cover, etc.
Additionally, a calorie refers to the amount of heat required to raise the temperature of a gram of water by one degree Celsius (°C).
Answer:
Temperature; surrounding; insulated.
Explanation:
A calorimeter measures the heat involved in reactions or other processes by measuring the Temperature of the materials surrounding the process. The calorimeter is insulated to prevent the transfer of heat outside the device.
Which event is an example of melting?
A. Wax drips down the side of a lit candle.
B. Perspiration dries on a person's skin.
C. Rain turns to ice pellets.
D. A mirror fogs up when someone takes a hot shower.
I’m just curious tbh
Answer:
A. Wax drips down the side of a lot candle.
Explanation:
The chemical change from solid to liquid. This is a combustion reaction, so carbon dioxide gas and water vapour is also produced but you can't see them
Answer:
A. Wax drips down the side of a lot candle.
Explanation:
Complete the following road map for converting volume of A to volume of B for a titration of aqueous solution A with aqueous solution B.
a. multiply by the molarity of B
b. multiply by the moles of B per moles of A
c. divide by the molarity of B
d. multiply by the molarity of A
e. divide by the molarity of A
f. multiply by the moles of A per moles of B
1. volume A (L)
2. moles A
3. moles B
4. volume B (L)
Answer:
Explanation:
The solution of known concentration is expressed as molarity. Molarity is the mole fraction of solute (i.e. the dissolved substance) per liter of the solution, Molarity is also commonly called molar concentration.
Mathematically;
[tex]\mathtt{Molarity = \dfrac{moles \ of \ solute}{ liters \ of \ solution}}[/tex]
To copy and complete the road map from the given question, we have the following array:
Volume A (L)
↓
d. multiplied by the molarity of A
↓
moles A
↓
b. multiplied by the moles of B / moles of A
↓
moles B
↓
c. divided by the molarity of B
↓
volume B (L)
Which of the following is not generally a characteristic of metal?
Ductility
O
Malleability
High melting point
Low boiling point
PLZZZZZZZZ HELPPPPPP
Answer:
482
Explanation:
