Answer:
The pH of a solution of 0.00278 M of HClO₄ is 2.56
Explanation:
pH is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance and is calculated as:
pH= - log [H⁺]= - log [H₃O⁺]
On the other hand , a Strong Acid is that acid that in an aqueous solution dissociates completely. In other words, a strong acid completely dissociates into hydrogen ions and anions in solution.
HClO₄ is a strong acid, so in aqueous solution it will be totally dissociated. Then, the concentration of protons is equal to the initial concentration of acid and the pH will be calculated:
pH= - log 0.00278
pH= 2.56
The pH of a solution of 0.00278 M of HClO₄ is 2.56
For the reaction2 C4H10 (g) + 13 O2 (g) → 8 CO2 (g) + 10 H2O (g)ΔH° is -125 kJ/mol and ΔS° is +253 J/K ∙ mol. This reaction is ____.A. spontaneous only at low temperatureB. spontaneous only at high temperatureC. spontaneous at all temperaturesD. nonspontaneous at all temperaturesE. unable to determine without more information
Answer:
C. spontaneous at all temperatures
Explanation:
The spontaneity of reaction is determined by the sign of the gibbs free energy.
A negative sign denotes that the reaction is spontaneous, positive sign means the reaction is not spontaneous.
From the question;
ΔS° = +253 J/K
ΔH° = -125 kJ/mol
ΔG = ΔH° - TΔS°
From the data given, the condition in which we can obtain a negative value of G, is at any value of T.
For any value of T, G would always be a negative value.
This means the correct option is option C.
A solution is prepared at that is initially in benzoic acid , a weak acid with , and in sodium benzoate . Calculate the pH of the solution. Round your answer to decimal places.
Answer:
[tex]pH=4.1[/tex]
Explanation:
Hello,
In this case, for a concentration of 0.42 M of benzoic acid whose Ka is 6.3x10⁻⁵ in 0.33 M sodium benzoate, we use the Henderson-Hasselbach equation to compute the required pH:
[tex]pH=pKa+log(\frac{[base]}{[acid]} )[/tex]
Whereas the concentration of the base is 0.33 M and the concentration of the acid is 0.42 M, thereby, we obtain:
[tex]pH=-log(Ka)+log(\frac{[base]}{[acid]} )\\\\pH=-log(6.3x10^{-5})+log(\frac{0.33M}{0.42M} )\\\\pH=4.1[/tex]
Regards.
A block of aluminum occupies a volume of 0.015 L and has a mass of 40.5 g. What is its density
Answer:
Density = 2700 g/LExplanation:
Density of a substance can be found by using the formula
[tex]Density = \frac{mass}{volume} [/tex]
From the question
volume = 0.015 L
mass = 40.5 g
Substitute the values into the above formula and solve for the Density
That's
[tex]Density = \frac{40.5}{0.015} [/tex]
We have the final answer as
Density = 2700 g/L
Hope this helps you
Which one of these salts will form a neutral solution on dissolving in water? KNO2 NaCN NaCl NH4NO3 FeCl3
Answer:
NaCl
Explanation:
Salts whose ion cannot hydrolyse form neutral solutions; not having alkaline nor acidic properties.
All the other salts would dissociate to form solution or strong acid ad weak bases or vice versa, which then determines their alkalinity or acidity: all except sodium chloride, NaCl.
I hope this explanation was helpful and clear.
When dipentyl ether is treated with HI, what type of reaction occurs? both SN1 and SN2 SN2 E1 SN1 E2
Answer:
SN2
Explanation:
The first step of ether cleavage is the protonation of the ether since ROH is a better leaving group than RO-.
The second step of the reaction may proceed by either SN1 or SN2 mechanism depending on the structure of the ether. Methyl and primary ethers react with HI by SN2 mechanism while tertiary ethers react with HI by SN1 mechanism. Secondary ethers react with HI by a mixture of both mechanisms.
Dipentyl ether is a primary ether hence when treated with HI, the reaction with HI proceeds by SN2 mechanism as explained above.
g The chemicals above are dissolved in water to make a solution. Which ones will conduct electricity
Answer:
This question is incomplete
Explanation:
Although, the question above is incomplete, however the correct option can be deduced from the explanation below.
Compounds/chemicals that dissolve in water to conduct electricity are Ionic/electrovalent compounds. Ionic compounds/salts are compounds that are held together by ionic/electrovalent bond. These compounds dissociate in water to form ions; the dissociated ions formed are the carriers of electric charges hence enabling the salt solution conduct electricity. Examples of these electrovalent/ionic compounds include NaCl, CaCl₂, CsF and MgO.
NOTE: Identify the ionic/electrovalent compounds in the options (from the completed question) to get your answer.
So our professor didn't go over this but is freshly cut sodium, but rapidly tarnishes on contact with air a physical or chemical property?
Answer:
Hey!
After the slight confusion (haha)...
Your answer should be a CHEMICAL CHANGE / PROPERTY
Explanation:
Its CHEMICAL because the sodium has reacted with the air (oxygen in technical terms) which then forms SODIUM OXIDE...the tarnishing of the cut sodium surface it a thin layer of the SODIUM OXIDE...
HOPE THIS HELPED!
A sample of mass 6.814 grams is added to another sample weighing 0.08753 grams.
The subsequent mixture is then divided into exactly 3 equal parts. One of those parts has the yield multiplied by 7.6335 times; what is the final mass?
Answer:
17.5609g
Explanation:
According to the question, a sample of mass 6.814 grams is added to another sample weighing 0.08753 grams. That is weight of sample 1 + weight of sample 2;
6.814 + 0.08753 = 6.90153grams
Next, the subsequent mixture is then divided into exactly 3 equal parts i.e. 6.90153grams divided by 3
= 6.90153/3
= 2.30051grams.
One of the equal parts is 2.30051grams, which is then multiplied by 7.6335 times I.e. 2.30051 × 7.6335 = 17.5609grams
Therefore, the final mass is 17.5609grams
Why is Hydrogen Peroxide lethal to drink if it is only composed of one more molecule of oxygen than water?
Answer: Hydrogen peroxide is a clear, odorless, and colorless liquid consisting of hydrogen and oxygen. It’s available in dilutions ranging from 3–90%, some of which are sometimes used as an alternative health remedy.
Advocates suggest that drinking a few drops of hydrogen peroxide diluted in water may help treat a range of illnesses, including diabetes and even some forms of cancer.
However, medical professionals warn against the dangers of this practice.
This article takes a look at the latest evidence to determine whether the benefits of drinking hydrogen peroxide outweigh its potential risks.
Explanation:
If you have ingested small amounts of 3% hydrogen peroxide, call your local poison control helpline for assistance. If you have swallowed larger amounts or higher concentrations, seek immediate medical assistance from an emergency room.
The bottom line
Hydrogen peroxide is touted as an alternative health remedy for a range of health conditions.
However, there’s no scientific evidence that drinking it yields any benefits. Plus, doing so is linked to dangerous side effects, including breathing problems, severe gut damage, and in some cases, death.
For these reasons, drinking any concentration or amount of hydrogen peroxide is not recommended.
Barry Bonds hit 62 homeruns in one season. Given there are 4 bases and each base is
90 feet apart, how many kilometers did he run?
Answer:
6.803136 KM
Explanation:
I multiplied 90 by 4 to get 360 feet, or the distance of each homerun. 360 times 62 gave me 22,320.
22,320 converted to KM is 6.803136 Km
you may want to round it up, but I would use the precise answer.
Barry Bonds is a former American baseball player that played in various leagues and seasons. In 62 home runs and 4 bases, he ran around 6.803136 Kilometers.
What is the unitary method?The unitary method is the mathematical technique to estimate the values of units from a single value by multiplication and division. It uses the cross multiplication application to find the other values.
Given,
Number of bases = 4
Distance between each base = 90 feet apart
Number of home runs in one season = 62
By using the cross multiplication and unitary method the distance can be calculated as:
1 base = 90 feet apart
4 base = X feet
Solving for X as:
X = 90 × 4
= 360 feet
If one homerun = 360 feet
Then, 62 homerun = X feet
X is calculated as:
X = 360 × 62
= 22,320 feet
The units from feet to km are converted as:
1 feet = 0.0003048 km
Then, 22,320 feet = 6.803136 km
Therefore, Barry Bonds ran 6.803136 km.
Learn more about the unitary method, here:
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How does the amount of sunlight affect the number of eggs laid by a chicken?
Explanation:
The amount of daylight hours affects a chicken's reproductive cycle. Hens will begin laying when the amount of daylight reaches 14 hours per day during early spring. Maximum egg laying will occur when the day length reaches 16 hours per day
Show the difference in the reactivity of Na,Ca,Mg,Al,Fe,Cu with H2O
Answer:
Explanation:
Na react with H2O to form NAOH
2 Na+2H2O....................2NAOH + H2
Ca react with water and form calcium hydroxide
Ca + 2H2O........................Ca(OH)2
Mg react with water and form Magnesium hydroxide
Mg +2H2O .........................Mg(OH)2 however this coating of mg(oh)2 prevent it from further reaction
Fe react with water and form ferric hydride
3Fe +H2O.......................2 FeH +FeO
copper do not react with water
g The large negative free energy of hydrolysis of Phosphoenolpyruvate is largely due to _______________ of the enol pyruvate.
Answer:
hello your question lacks some parts below are the missing option
A. hydrophobic interaction
B. nucleophilic attack
C. tautomerization
D. resonance
answer : Tautomerization ( C )
Explanation:
The large negative free energy of hydrolysis of Phosphoenolpyruvate is largely due to tautomerization of the enol pyruvate. tautomerism of enol takes place by transferring proton from in an intramolecular way.
one of the most common tautomerism is keto-enol which makes uses of either an acid or base as a catalyst
20g of ideal gas contains only atoms of s and o occupies 5.6l at ntp what is the mol wt of gas
Answer:
20g gas contains and this so allow in tha 36G in per laar
Explanation:
What volume (mL) of a 0.3428 M HCl(aq) solution is required to completely neutralize 23.55 mL of a 0.2350 M Ba(OH)2(aq) solution
Answer:
32.29 mL
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
2HCl(aq)+ Ba(OH)2(aq) —> BaCl2(aq) + 2H2O
From the balanced equation above, the following were obtained:
Mole ratio of the acid (nA) = 2
Mole ratio of the base (nB) = 1
Next, data were obtained from. This include the following:
Molarity of acid, HCl (Ma) = 0.3428 M
Volume of acid, HCl (Va) =.?
Molarity of base, Ba(OH)2 (Mb) = 0.2350 M
Volume of base, Ba(OH)2 (Vb) = 23.55 mL
Finally, we shall determine the volume of the acid, HCl required for the reaction as follow:
MaVa /MbVb = nA/nB
0.3428 × Va / 0.2350 × 23.55 = 2/1
Cross multiply
0.3428 × Va = 0.2350 × 23.55 × 2
Divide both side by 0.3428
Va = (0.2350 × 23.55 × 2) / 0.3428
Va = 32.29 mL
Therefore, the volume of acid, HCl required for the reaction is 32.29 mL
is another way in which nitrogen gets fixed in the soil
Answer:
through Rhizobium bacteria
classify the organisms based on what they eat. producer consumer decomposer
Lowest - Producer - plants (mostly)
They get food by converting sunlight into nutrients
Middle - Consumer - example animals
They eat other living things such as plants or other animals for their nutrients
Top - Decomposer - bacteria/microorganisms
They decompose dead body
sorry if im wrong
At STP how many liters of NH3 can be produced from the reaction of 2.00 mol of N2 with 2.00 mol of H2
Answer:
29.9L of NH₃ are produced
Explanation:
The reaction of H2 with N2 to produce NH3 is:
3 H2 + N2 → 2 NH3
For a complete reaction of 2.00 moles of H2 there are required:
2.00 moles H2 * (1 mole N2 / 3.00 moles H2) = 0.667 moles N2
The limiting reactant is hydrogen.
The volume of hydrogen using PV = nRT is (STP: 273.15K; 1atm):
V = nRT / P
V = 2.00mol * 0.082atmL/molK*273.15K / 1atm
V = 44.8L
As we know for the reaction, 3 moles of hydrogen produce 2 moles of NH3.
The moles of H2 produced are:
2mol H2* (2mol NH3 / 3mol H2) = 1.33 moles NH3 are produced
Under pressure and temperature constant (STP) you can apply The Avogadro's law that states:
V₁ / n₁ = V₂ / n₂
Where V is volume and n moles of 1, the first gas and 2, the second gas.
V₁ / n₁ = V₂ / n₂
44.8L / 2.00mol = V₂ / 1.33 moles
V₂ =
29.9L of NH₃ are produced
Select the single best answer. When 2-heptyne was treated with aqueous sulfuric acid containing mercury(II) sulfate, two products, each having the molecular formula C7H14O, were obtained in approximately equal amounts. What are these two compounds
Answer:
heptan-3-one and heptan-2-one
Explanation:
In this case, we must remember what the products of this reaction are. An alkyne in the presence of HgSO4 and H2SO4 will produce a ketone. But, in the triple bond, we have two carbons, therefore the carbonyl group can be placed on any of the carbons of the triple bond.
In figure 1 we have the general reaction. At C = O it can be added to the carbon on the left (red carbon) or the carbon on the right (blue carbon).
Following this logic, for 2-heptyne the carbonyl group can be added to carbon 2 producing heptan-2-one. Similarly, the carbonyl group can be added to carbon 3 producing heptan-3-one. (See figure 2)
Which of the following correctly describes a mixture? (4 points) a The particles are chemically bonded together, and they retain their individual physical and chemical properties. b The particles are not chemically bonded, and they can only combine in certain set ratios. c The particles do not retain their individual chemical properties, and they can only be separated by chemical means. d The particles have no set ratio for how to combine, and they can be separated by physical means.
Answer:
the answer is B the particles are not chemically bonded, they can only be combined in a certain set ratios
Explanation:
2The higher the numbers on the NFPA diamond, the more _____ the substance is.
ARare incorrect answer
BDangerous incorrect answer
CPure incorrect answer
DSafe
The correct answer is B. Dangerous
Explanation:
The NFPA diamond is used to show how safe or dangerous a substance or material is based on four main categories: Health (blue), Flammability (red), Instability (yellow), special hazards (white). Moreover, the three first hazards are expressed using numbers from 0 to 4, in which 0 means no hazard while 4 is the most dangerous category. For example, in the health square finding 0 means the substance represents no hazard for health, while 4 means the substance is lethal. This means the higher the number in this diamond, the most dangerous the substance is.
Some people argue that a policy of putting out wildfires is having a negative long-term effect on the number and strength of wildfires. Suggest why this could be the case.
Answer:
The reason for this is that putting out the fires only postpones the fire outbreak to a later date, and there is the fear of the fire outbreak being more sever when it actually comes.
When wildfires burn, they clean up the forest off dead trees and falling logs. Also dried leaves and twigs and unnecessarily dense vegetation is cleared up by the fire. These materials are the main fuel of these wildfires. Putting out these fires, especially those that start naturally means that these fuel that should be cleaned up are allowed to accumulate so that when the fire actually happens, it does so with an unnatural intensity. Also, when fire burns, the ashes that are left act as nutrition for the forest, and the forest is allowed to regrow; reborn from the ashes. The only cases that might need human intervention is when the fire is human caused or due to human activities. Natural causes of fire can be due to a very high temperature, lightning striking a tree, etc.
Calculate the density of an object with a mass of 220 and a volume of 145mL.
Answer:
1.52 g/mL
Explanation:
The formula for finding the density of an object is d = m/v, or density = mass divided by volume.
Therefore, we can input the two values and solve for d.
d = 220/145
d = 44/29
d ≈ 1.52 g/mL
A pool is 59.8 m long and 26.6 m wide. If the average depth of water is 3.70 ft, what is the mass (in kg) of water in the pool? Enter your answer in scientific notation. The density of water is 1.0 g/mL.
Given :
Length , l = 59.8 m.
Breadth , b = 26.6 m.
Depth , d = 3.7 ft .
Density of water , [tex]\rho=1\ g/ml=1000\ kg/m^3[/tex] .
To Find :
Mass of water in pool .
Solution :
First we will covert depth into m from ft .
[tex]1\ ft =0.3\ m[/tex]
For ,
[tex]3.7\ ft=0.3\times 3.7\ m\\3.7\ ft=1.11\ m[/tex]
So , volume of pool is :
[tex]V=59.8\times 26.6\times 1.11\ m^3\\\\V=1765.65\ m^3[/tex]
We know , density is given by :
[tex]\rho=\dfrac{m}{V}[/tex]
So , [tex]m=\rho V[/tex]
Putting given values in above equation :
[tex]m=1000\times 1765.65\ kg\\\\m=1.77\times 10^6\ kg[/tex]
Hence , this is the required solution.
The value of mass in kg is [tex]1.76\times10^{6} \ kg[/tex].
Length , l = 59.8 m.
Breadth , b = 26.6 m.
Depth , d = 3.7 ft
Covert depth into m from ft.[tex]1ft=0.3m[/tex][tex]3.7ft=0.3\times3.7\\=1.11m[/tex]
Volume of pool is as follows:-
[tex]Volume=59.8\times26.6\times1.11\\=1765.65\ m^{3}\\=1765.65\times1000\ L=1765650 L[/tex]
Density:-It is defined as mass per unit volume.
[tex]Density=\frac{Mass}{Volume}[/tex]
Substitute 1.0 kg/L for density and 1765650 L for volume for the calculation of mass as follows:-
[tex]m=1kg/L \times1765650\ L\\\\=1.76\times10^{6} \ kg[/tex]
To know more about:-
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Johnny was finished with his
experiment so he placed all of his
unused chemicals back into their
original containers. What should
Johnny have done instead?
The sono
Cell membranes are largely hydrophobic structures. Which compound will pass through a membrane more easily, glucose or 2,4-dinitrophenol? Explain.
Answer:
2,4-dinitrophenol
Explanation:
A hydrophobic molecule does not dissolve nor mix with water. The cell membranes are made up of hydrophobic lipids. Hence, hydrophobic molecules easily pass through the cell membrane.
Glucose is partly hydrophilic hence it is transported across the cell membrane by special proteins. However, 2,4-dinitrophenol is a hydrophobic molecule thus it is easily transported across the cell membrane.
A 1.000 g sample of nitrogen combined with a 0.0720 g sample of hydrogen to form N2H2. What compound is formed if 1.000 g of nitrogen combines with 0.2160 g of hydrogen?
N2H6 NH3 NH4+ N4H4
Answer:
N₂H₆
Explanation:
A 1.000 g sample of nitrogen combined with a 0.0720 g sample of hydrogen to form N₂H₂ .
1.000 g of nitrogen combines with 0.2160 g of hydrogen in the next compound .
In this compound the component of nitrogen remains the same but the component of hydrogen becomes .2160 / .0720 = 3 times .
Hence component of hydrogen in the new compound will change from
H2 to H6 .
Hence the chemical formula of new compound will be
N₂H₆ .
2. Explain what an isotope is and give two important physical properties of isotopes that make them useful in biological research. Define half-life.
Answer:
isotope is a variants of a particular chemical element which differ in neutron number, and consequently in nucleon number.All isotopes of a given element have the same number of protons but different number of neutrons in each atom.The 2 important physical properties of isotope is1.Melting Points2.Boiling PointsAnatomy+ Chemistry List the 8 common ions in the human body and their charge. Identify each as a cation or anion.
Answer:
Sodium ions - Na⁺ - cation
Potassium ions - K⁺ cation
Chloride ions - Cl⁻ anion
Magnesium ions - Mg²⁺ cation
Calcium ions - Ca²⁺ cation
Phosphate ions - P³⁻ anion
Iron ions - Fe²⁺ cation
Zinc ions - Zn⁺ cation
Explanation:
Following is a list of 8 common but essential ions in the cells and fluids of human bodies:
1. Sodium ions helps in regulation and control the level of body fluids
2. Potassium ions help regulate cellular functions
3. Calcium ions are essential for building and maintaining strength bones and teeth. and have role in blood clotting, muscle contraction, and the transmission of nerve signals to cells.
4. Chloride ions are the main anions found outside body cells. They acts as counterions
5. Magnesium ions present in the bones
6. Phosphate ions present in body fluids act as the counterions.
7. Iron
8. Zinc
John had seen people sprinkle salt on ice in the winter. The salt appeared to melt the ice. He decided to sprinkle salt on a larger block of ice. Then he added food coloring so he better could see the results. How did creativity help John in this experiment? A. It helped him use materials in a new way to help him gather data. B. It helped him reason through the results of his experiments. C. It helped him follow the steps of the procedure precisely. D. It helped him remember something from his past.
The correct answer is A. It helped him use materials in a new way to help him gather data.
Explanation:
The use of food coloring in this experiment makes it easier to observe how salt affects ice and if this helps ice to melt. This implies by adding food coloring John can better observe the phenomenon he is studying and gather precisely data about this phenomenon, which would also help him to draw accurate conclusions. In this context, the use of food coloring shows creativity because he is using this material as an alternative way and this use would help him in the stage of gathering data (option A), which is the stage that follows after implementing experiments.
Answer:
A
Explanation:
Just got it right on my quiz!! I hope this helps! <3