Answer:
pH = 6.167
Explanation:
The weak acid, HX, reacts with NaOH as follows:
HX + NaOH → NaX + H₂O
Where 1 mole of HX with 1 mole of NaOH produce 1 mole of NaX (The conjugate base of the weak acid).
Now, using H-H equation:
pH = pKa + log [NaX] / [HX]
Where pH is the pH of the buffer
pKa is -log Ka = 6.167
And [NaX] [HX] are the molar concentrations of each specie
Now, at the neutralization of the half of HX, the other half is as NaX, that means:
[NaX] = [HX]
And:
pH = pKa + log [NaX] / [HX]
pH = 6.167 + log 1
pH = 6.167Helen is studying the properties of solids. She is comparing the wooden cube and the steel cube shown in the picture below.
mc065-1
Which property is the same for the two cubes?
color
luster
texture
volume
balance and find out the coefficients of reactions and products
Answer:
2, 1, 1, 4.
Explanation:
Hello there!
In this case, for the given chemical reaction:
[tex]H_2SO_4+Pb(OH)_4\rightarrow Pb(SO_4)_2+H_2O\\[/tex]
We can see how there is one SO4 on the left and two on the right, thus, we add a 2 in front of H2SO4:
[tex]2H_2SO_4+Pb(OH)_4\rightarrow Pb(SO_4)_2+H_2O\\[/tex]
Next, since there are 8 atoms of hydrogen on the left and two on the right, we add a 4 in front of H2O to obtain:
[tex]2H_2SO_4+Pb(OH)_4\rightarrow Pb(SO_4)_2+4H_2O\\[/tex]
Which is now balanced so the coefficients 2, 1, 1, 4.
Best regards!
suppose you are analyzing an antacid that contains Mg(OH)2 and Al(OH)3 in a 1:1 molar ratio. The antacid was neutralized with an excess of 0.500 M HCl, and the excess HCl was then back titrated with 0.500 M NaOH. The following data was obtained: Volume of 0.500 M HCl utilized: 38.25 mL Volume of 0.500 M NaOH utilized: 3.60 mL Calculate the masses of Mg(OH)2 and Al(OH)3 contained in the antacid.
Answer:
0.202g of Mg(OH)₂ and 0.270g of Al(OH)₃
Explanation:
The OH⁻ ions of the Mg(OH)2 and Al(OH)3 reacts with the HCl. The HCl in excess reacts with the NaOH. To solve this question we must find the moles of HCl that react in the beginning with the antiacid and as the ratio is 1:1 we can find the moles of Mg(OH)2 and Al(OH)3. The reactions are:
OH⁻ + HCl → Cl⁻ + H₂O
HCl + NaOH → NaCl + H₂O
Moles HCl added:
0.03825L * (0.500mol / L) = 0.019125 moles
Moles NaOH utilized:
0.0036L * (0.500mol / L) = 0.0018 moles
Moles HCl that react = Moles OH⁻ in the antiacid
0.019125 moles - 0.0018moles =
0.017325 moles OH⁻ in the antiacid
As the ratio is 1:1. the moles Mg(OH)2 = Moles Al(OH)3
And these 5 hydroxides produce 0.017325 moles:
5X = 0.017325 moles
X = 3.465x10⁻³ moles
Where X are moles of both Mg(OH)2 and Moles Al(OH)3
Mass -Molar mass: 58.3197 g/mol-:
3.465x10⁻³ moles * (58.3197g/mol) =
0.202g of Mg(OH)₂And
Mass -Molar mass: 78g/mol-:
3.465x10⁻³ moles * (78g/mol) =
0.270g of Al(OH)₃2. A 0.45g sample of mineral ore is analyzed for chromium and found to contain
0.560mg Cr2O3. Express the concentration of Cr2O3 in the sample as:
(a) Percent (%)
(b) Parts per thousand (ppt)
(c) Parts per million (ppm)
(d) Parts per billion (ppb)
Answer:
Explanation: I don't know
Electrolysis is used in the electroplating of metals. The same amount of current is passed through separate aqueous solutions of CuSO4, Sn(SO4)2 and Cr2(SO4)3 in separate electrolytic cells for the same amount of time. State and explain which cell would deposit the greatest amount (in mol) of metal. Identify the electrode at which the metal is deposited.
Answer:
CuSO4 cell will have the greatest amount of deposit among all three. The deposit will occur at the cathode
Explanation:
The valence of the elements in this case is as follows -
Cu - 2e-
Sn - 4e-
Cr - 3e-
CuSO4 cell will have the greatest amount of deposit among all three
The atoms of copper metal will deposit at the cathode. At the cathode, the least number of moles of electrons needed .
Hence, more amount of copper can be extracted out by the electrolyte
What can you infer about the air pressures over the land and ocean? Explain your answer.
Answer:
Answer: During the day, the sun heats up both the ocean surface and the land. ... The wind will blow from the higher pressure over the water to lower pressure over the land causing the sea breeze. The sea breeze strength will vary depending on the temperature difference between the land and the ocean.
Explanation:
A chemist needs to determine the concentration of a solution of nitric acid, HNO3. She puts 905 mL of the acid in a flask along with a few drops of indicator. She then slowly adds 0.200 M Ba(OH)2 to the flask until the solution turns pink, indicating the equivalence point of the titration. She notes that 235 mL of Ba(OH)2 was needed to reach the equivalence point.
Required:
a. How many moles of Ba(OH)2 are present in 225 mL of 0.200 M Ba(OH)2?
b. How many moles of HNO3 are present if 4.50 x 10^2 mol of Ba(OH)2 was needed to neutralize the acid solution? (Express your answer numerically in moles)
Answer:
See explanation
Explanation:
The equation of the reaction is;
2HNO3(aq) + Ba(OH)2(aq) -------->Ba(NO3)2(aq) + 2H2O(l)
a) The number of moles of Ba(OH)2 = 225/1000 * 0.200
= 0.045 moles
From the reaction equation;
2 moles of HNO3 require 1 mole of Ba(OH)2
x moles of HNO3 require 4.50 x 10^2 mol of Ba(OH)2
x = 4.50 x 10^2 * 2/1
x = 9 x 10^2 moles of HNO3
Explain if the reaction of iron and copper sulfate supports the Law of Conservation of Mass. Use evidence and scientific reasoning to support your answer.
What's a household item that has  electrical energy
Answer:
Washing machine.
Dryer.
Television.
Cell phone.
Explanation:
Answer:
Washer and dryer, TV, Cell phone
Explanation:
What is the ratio by atoms of elements present in hafnium phosphite?
1:3:4
3:6:2
3:4:12
1:6:15
3:6:2 is the correct answer
I need help pls!!!!
Answer:
A
Explanation:
jsgsnsbnss care about explaimi
A reaction was experimentally determined to follow the rate law, Rate = k[A] where k = 0.15 s-1. Starting with [A]o = 0.225M, how many seconds will it take for [A]t = 0.0350M?
Answer:
The time the reaction takes is 12.4s
Explanation:
A reaction that follows the rate law:
Rate =k[A] is order 1 and follows the equation:
Ln[A] = -kt + ln[A]₀
Where [A] is concentration of the reaction after time t: 0.0350M
k is rate constant = 0.15s⁻¹
t is time in seconds
[A]⁰ is initial concentration = 0.225M
Ln[0.0350] = -0.15s⁻¹*t + ln[0.225]
-1.86075 = -0.15s⁻¹*t
12.4s = t
The time the reaction takes is 12.4s
Which of the following statements are true? Select all answers that are true (this might be more than one answer). Select one or more: a. London dispersion forces are the only type of intermolecular forces that nonpolar molecules exhibit. b. Molecules that have only London dispersion forces will always be gases at room temperature (25 oC). c. None of the listed answers are true. d. The molecules in SO2 (g) exhibit dipole-dipole intermolecular interactions. e. CH3CH2CH3 has stronger London dispersion forces than does CH4.
Answer:
London dispersion forces are the only type of intermolecular forces that nonpolar molecules exhibit.
The molecules in SO2 (g) exhibit dipole-dipole intermolecular interactions.
CH3CH2CH3 has stronger London dispersion forces than does CH4.
Explanation:
London forces result from temporary shifts or distortion in the electron cloud of non-polar molecules. London forces occur in all substances; whether polar or non-polar. However, it is the only kind of intermolecular force in non-polar molecules and noble gases.
Polarity in a molecule stems from difference in electronegativity between the atoms in the molecule. SO2 is a polar molecule due to the magnitude of electronegativity difference between sulphur and oxygen. Hence SO2 exhibit dipole-dipole intermolecular interactions since it is a polar molecule.
The magnitude of London dispersion forces depends on the molar mass and surface area of molecules. CH3CH2CH3 has a higher molar mass and larger surface area than CH4 hence CH3CH2CH3 has stronger London dispersion forces than does CH4.
The following statements which are true include
London dispersion forces are the only type of intermolecular forces that nonpolar molecules exhibit.The molecules in SO2 (g) exhibit dipole-dipole intermolecular interactions.CH3CH2CH3 has stronger London dispersion forces than does CH4.London forces are the only type of intermolecular force found in non polar
compounds and they are responsible for their attractive interactions.
The molecules in SO2 (g) exhibit dipole-dipole intermolecular interactions as
a result of it being polar.
CH3CH2CH3 has stronger London dispersion forces than does CH4
because it is more non-polar and it is the characteristic attraction found in
non-polar compounds.
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A gas cylinder is filled with 5.50 moles of oxygen gas at 83°C. The piston is compressed to yield a pressure of
400.0 kPa. What is the volume inside the cylinder?
Answer:
volume=0.04322m3
Explanation:
acording to ideal gas equation that PV=nRT
Which of these would a mechanical engineer do?
Answer:
I dont see the answers
Explanation:
Please help is for today
Answer:
Our bodies are designed to regulate our temperature. When it's cold outside, your body makes sure to keep the blood flowing to your core and vital organs to keep them warm. This can change the amount of blood flow to your hands and feet, making them feel cold
In what direction does thermal energy transfer?
Answer:
Either direction
Explanation:
If you cook food it would go from cold to hot. If you were to put a drink in the fridge it would go from hot to cold. So it is either direction.
more reactive material can help to stop iron rusting please answer true or false
Answer:
true
Explanation:
and don't look up the link everyone says it's scam bots
Need help is label a warm area or is b Orr are they both warm
Answer:
your image is a blavk screen so we cant tell
Explanation:
Explain why each of these elements occur as diatomic molecules, Match the words in the left column to the appropriate blanks in the sentences on the right.
triple
double
octet
single
duet
When two hydrogen atoms pair together, they form a ____bond to achieve a complete _______which is a stable configuration.
When two halogens poir together,they form a________bond to achieve a complete_______ which is a stable configuration
to achieve a completo
When two oxygen atoma pair together, they form a_________bond to achieve a complete which is a stable configuration
When two nitrogen atomo poir together, they form a_________bond to achieve a complete which is a stable configuration
Answer: When two hydrogen atoms pair together, they form a single bond to achieve a complete duet which is a stable configuration.
When two halogens poir together,they form a single bond to achieve a complete octet which is a stable configuration
When two oxygen atoma pair together, they form a double bond to achieve a complete octet which is a stable configuration
When two nitrogen atoms pair together, they form a triple bond to achieve a complete octet which is a stable configuration
Explanation:
The tendency of atoms to achieve a noble gas configuration that is eight valence electrons is said to be octet rule. This is done to attain noble gas configuration and stability.
In order to attain stability the atoms tends to have eight electrons in its valence shell which can be obtained by either by sharing of electrons or complete transfer of electrons.
Hydrogen [tex](H:1s^1)[/tex] has one valence electron each, so sharing of electrons result in formation of single bond and the same electron configuration as the Helium and thus complete its duet.
Halogens [tex](F:1s^22s^22p^5)[/tex] have 7 valence electron each, so sharing of electrons result in formation of single bond. The stable noble gas configuration is attained and thus complete its octet.
Oxygen [tex](O:1s^22s^22p^4)[/tex] has six valence electrons each, so sharing of two electrons result in a double bond. The stable noble gas configuration is attained and thus complete its octet.
Nitrogen [tex](N:1s^22s^22p^3)[/tex] has 5 valence electrons, so sharing of three electrons result in a triple bond. The stable noble gas configuration is attained and thus complete its duet.
A 250 mL beaker is submerged in a large container of Liquid X and turned upside down, and another 250 mL beaker is submerged and turned upside down in a large container of Liquid Y. Hydrogen (H2) gas is bubbled into each upside-down beaker until 100 mL of liquid has been displaced. The masses m X and my of hydrogen inside each beaker is then chemically determined.
a. mx will be greater than my
b. m x will be less than my
c. mx will be equal to my
d. It's impossible to predict whether mx or my will be greater without more information.
Answer:
Mx will be less than My.
Explanation:
The correct option is - Mx will be less than My.
Because, liquid X have been higher viscosity and vapor pressure than liquid B.
Vapor pressure of liquid A is greater, so the amount of liquid X will vaporized greater and H2 gas has been displaced greater from the beaker as compared to liquid Y.
The amount of H2 in liquid Y remains greater in beaker as compared to liquid X.
So, Mx will be less than My.
How many moles are in 6 x 10^23 molecules of H2O
Which of the following would be considered renewable resources? You may choose more than one.
oil
corn
clean air
forests
Answer:
clean air
Explanation:
QUESTION 7
When excess magnesium was reacted with dilute sulphuric acid, the reaction was fast at first but
gradually became slower and finally stopped.
Which of the following describe the reaction?
A.
B.
The magnesium was used up.
The sulphuric acid was used up.
The temperature of the mixture decreased.
The magnesium particles became coated with hydrogen gas.
C.
D.
The reactant present in more amounts is called excess reagent. In the reaction between Mg and sulphuric acid, the reaction gradually stopped due to the consumption of the acid. Thus, option B is correct.
What is an excess reagent?An excess reagent is a chemical reactant present in more quantity than the other substance or reactant in the reaction. They are not totally consumed after the reaction ends, unlike the limiting reagent.
In the reaction, magnesium is the excess reagent while dilute sulphuric acid is a limiting reagent that determines the reaction rate and the product formation. At first, the reaction will be fast but gradually will become slow as all dilute sulphuric acid will be consumed slowing downs and stopping the reaction.
Therefore, dilute sulphuric acid will be used up at the end of the reaction.
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What was the purpose of letting the transformed cells sit in LB for a few minutes before spreading them onto the plates?
A. This allows time for the cells to express the antibiotic resistance gene
B. This allows the cells to take up the plasmid after the heat shock procedure
C. This allows time for the cells to warm up before plating
D. This allows cells time to start glowing green
Glucose and alcohol Contain hydrogen
but they are not adds Why?
Answer:
Ans. Alcohols and glucose though contain hydrogen but do not ionise in the solution to produce H+ ions. This is proved by the fact that there solutions do not conduct electricity.
the experimental control is the ?
A. Dependent variable
B. Design of the experiment.
C. Outcome of the experiment
D. the standard against which the results are measured .
Answer:
D. In an experiment, one of the variables will be giving a placebo and the other, a treatment
Explanation:
Photosynthesis, the process by which green plants and certain other organisms transform light energy into chemical energy. During photosynthesis in green plants, light energy is captured and used to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds.
PLEASE HELP WILL GIVE 20PTS AND WILL MARK BRAINLIEST FOR RIGHT ANSWER!!!
Water can be formed from the synthesis reaction of hydrogen with oxygen:
2 H2 (g) + O2 (g) → 2 H2O (g)
The complete reaction of 5.12 Liters of O2 with excess hydrogen produces how many moles of H2O?
A) 10.24 moles H2O
B) 114.7 moles H2O
C) 0.457 moles H2O
D) 5.12 moles H2O
Answer:
C) 0.457
Explanation:
The ratio between O2 and H2O is 1:2 according to the balanced equation. You can find how many moles is O2 by : 5.12/22.4 = 0.22857 ( 1 mole = 22.4 litters)
Moles of H2O will be 0.22857 * 2 = 0.457142.
Therefore answer C)
Identify the Lewis base in this balanced equation: 6 upper H subscript 2 upper O plus UPper C r (upper H subscript 2 upper O) subscript 6 superscript 3 plus. H2O Cr3+ Cr(H2O)63+
The Lewis base that we can see in the equation is [tex]H_{2} O[/tex]
What is the Lewis base?We have to bear in mind that the Lewis base is the substance that is able to donate a pair of electrons. The substances that is able to accept the pair of electrons is what we call the Lewis acid.
The Lewis acid must possess a space for the addition of an electron pair while the Lewis base would have to be a specie that has a lone pair of electrons or has a negative charge. Thus the water molecule would serve as a Lewis base in this regard.
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Answer:
6 upper H subscript 2 upper O plus UPper C r (upper H subscript 2 upper O) subscript 6 superscript 3 plus.
✔ H2O or A.)
Cr3+
Cr(H2O)63+
Use mass-mass calculation, determine how many grams of sodium chloride SHOULD have been produced from the amount of sodium bicarbonate in mass (B.)
Answer:
where is the question???