Answer:
Mean
Explanation:
The mean of a series of measurements is calculated when all the measurements are added up and then divided by the number of measurements taken, as follows:
Sum of Measurements = 20.73 + 20.76 + 20.68 + 20.75 = 82.92As there are 4 measurements, the mean is:
Mean = 82.92 / 4 = 20.73Answer:
A
Explanation:
Make tag question.
neither of them plays cricket,......?
Answer:
neither of them plays cricket,does anyone?
Explanation:
I know you will think I its weird but it is the rule of grammar and 100% correct!
Answer:
neither of them plays cricket, do you?
Explanation:
A buffer solution contains 0.475 M nitrous acid and 0.302 M sodium nitrite . If 0.0224 moles of potassium hydroxide are added to 150 mL of this buffer, what is the pH of the resulting solution
Answer: The pH of the resulting solution will be 3.001
Explanation:
Molarity is calculated by using the equation:
[tex]\text{Molarity}=\frac{\text{Moles}}{\text{Volume}}[/tex] ......(1)
We are given:
Moles of NaOH = 0.0224 moles
Molarity of nitrous acid = 0.475 M
Molarity of sodium nitrite = 0.302 M
Volume of solution = 150 mL = 0.150 L (Conversion factor: 1 L = 1000 mL)
Putting values in equation 1, we get:
[tex]\text{Moles of nitrous acid}=(0.475mol/L\times 0.150L)=0.07125mol[/tex]
[tex]\text{Moles of sodium nitrite}=(0.302mol/L\times 0.150L)=0.0453mol[/tex]
The chemical equation for the reaction of nitrous acid and NaOH follows:
[tex]HNO_2+NaOH\rightleftharpoons NaNO_2+H_2O[/tex]
I: 0.07125 0.0224 0.0453
C: -0.0224 -0.0224 +0.0224
E: 0.04885 - 0.0677
The power of the acid dissociation constant is the negative logarithm of the acid dissociation constant. The equation used is:
[tex]pK_a=-\log K_a[/tex] ......(2)
We know:
[tex]K_a[/tex] for nitrous acid = [tex]7.2\times 10^{-4}[/tex]
Using equation 2:
[tex]pK_a=-\log (7.2\times 10^{-4})=3.143[/tex]
To calculate the pH of the acidic buffer, the equation for Henderson-Hasselbalch is used:
[tex]pH=pK_a+ \log \frac{\text{[conjugate base]}}{\text{[acid]}}[/tex] .......(3)
Given values:
[tex][NaNO_2]=\frac{0.0677}{0.150}[/tex]
[tex][HNO_2]=\frac{0.04885}{0.150}[/tex]
[tex]pK_a=3.143[/tex]
Putting values in equation 3. we get:
[tex]pH=3.143-\log \frac{(0.0677/0.150)}{(0.04885/0.150)}\\\\pH=3.143-0.142\\\\pH=3.001[/tex]
Hence, the pH of the resulting solution will be 3.001
gress.
Newton's third law of motion
Is the following statement true or false?
When a large truck pushes a small car with a given force, the small car is applying an equal and opposite
force on the truck.
Choose 1 answer:
True
False
Answer:
true
Explanation:
the small car also has gravity making it heavy
Hydrogen bonds within liquid water are attractions between protons and hydroxide ions. are dipole-dipole attractions. are ion-induced dipole attractions. are attractions between protons and oxygen nuclei. are attractions between two hydrogen atoms.
Answer:
true because the bonds cannot be broken down
Which statement best describes the intermolecular forces between H2
molecules and NH3 molecules in the liquid phase?
A. Dipole-dipole forces are the strongest force between H2
molecules, and Van der Waals forces are the strongest force
between NH3 molecules.
B. Van der Waals forces are the strongest force between H2
molecules, and hydrogen bonding is the strongest force between
the NH3 molecules.
C. Hydrogen bonding is the strongest force between H, molecules
and between NH3 molecules.
D. Van der Waals forces are the strongest force between H2
molecules and between NH3 molecules.
Answer:
D. Van der Waals forces are the strongest force between H2
molecules and between NH3 molecules.
Explanation:
Van der Waal’s forces are the forces which arises due to disturbance in the electron density of the molecule.
These are usually found in non polar molecules. Hence N2 is said to exhibit this force.
Out of these Van der Waals is the weakest force.
What is the total number of atoms in one formula unit of MgSO4.7H2O?
Answer:
11.
O4 means 4 atoms of oxygen. H2O
has one atom of oxygen, so seven "units" of
H2O has 7.
Which area has atmospheric conditions that produce the lowest boiling point for water? OA. an ocean beach ОВ. an underground mine OC. a mountain peak OD. the middle of the ocean
Answer:
C. a mountain peak
Explanation:
Boiling occurs when vapour pressure equals atmospheric pressure. The vapour pressure is the pressure used by the gas leaving the pot and those returning. For boiling to occur, the vapour pressure must pass the atmospheric pressure around. At sea level, the atmospheric pressure is very high. With altitude, the air becomes thinner and atmospheric pressure becomes lower. With increasing altitude, the low atmospheric pressure makes the boiling point lower as a result of the decreasing pressure on the vapour. The boiling point can then easily be reached at higher altitudes. Therefore, a mountain peak has atmospheric conditions that produce the lowest boiling point for water as it has a higher altitude.
An elementary step is defined as a chemical collision in a reaction mechanism. A collection of different types of collisions makes up the reaction mechanism, so elementary steps provide a molecular view of the overall reaction.
a. True
b. False
Please select the word from the list that best fits the definition
Include skin, the respiratory system, the circulatory system, and inflammation
A. antibody
B. antigen
C.Natural Defences
D.active immunity
Answer:
I choose D option because may be it's correct
I believe it is c
Explanation:
because if u think about it and also do some research you would see that the circulatory system is a strong part of your body which can help u through natural defences if this sounds weird it's all in research but if it ain't c dont blame me for ruining your life- lol but yeah I think its c
The information code that an organism inherits can best be referred to as its -
O A genotype
B. territory
C. species
D. kingdom
Answer:
it will be no.A genotype
A reaction occurs in which hydrogen-1 and hydrogen-2 form helium-3. Is this a chemical reaction or a nuclear reaction, and how do you know?
The reaction is a nuclear reaction.
What are nuclear reactions?They are reactions involving the combination (fusion) or separation (fission) of nuclei of atoms.
If the nuclear reaction is fission, a heavier nucleus breaks down less heavy ones. If the reaction is a fusion, two nuclei combine to form a heavy one.
Hydrogen-1 combining with hydrogen-2 to form helium is a nuclear reaction because helium is heavier than each of the reactants.
More on nuclear reactions can be found here: https://brainly.com/question/16526663
#SPJ1
How many grams of potassium chloride will be needed to produce
829 grams of zinc chloride?
Answer:
[tex]2KCl + Zn {}^{2 + } → 2K {}^{ + } + ZnCl _{2} \\ molecular \: mass \: of \: zinc \: chloride = 65 + (35.5 \times 2) = 136 \: g \\ molecular \: mass \: of \: potassium \: chloride = 39 + 35.5 = 74.5 \: g
This week's imide synthesis involves two reactions. In the first reaction (24A), a(n) ________ bond is formed between the two reactants. Hint: What type of functional group is formed
Answer:
C - N Bond formation.
Explanation:
Imide synthesis is a chemical reaction in organic chemistry which consists of two acyl groups which bond to nitrogen atom. The compound structure is related to acid anhydrides. Imides are monoacyl which are used as valuable intermediates in organic synthesis.
A particle that travels around the nuceleus of an atom in orbitals is called?
How many moles of AICI3 are produced?
Answer:
please correct it, the question is incomplete
I need help and don’t understand, where does each chemical reaction go?
Answer:For the 1st box it starts with 250 and for the 2nd box it starts with CO(2).
Explanation:
Give two ways to make salt conduct.
Answer:
I think u willl get the answer fast in......
Answer:
this is because when a salt dissolves, its dissociated ions can move freely in solution, allowing a charge to flow. The resulting solution will conduct electricity because it contains ions.
Explanation:
For each of the salts on the left, match the salts on the right that can be compared directly, using Ksp values, to estimate solubilities. (If more than one salt on the right can be directly compared, include all the relevant salts by writing your answer as a string of characters without punctuation, e.g, ABC.) fill in the blank 1 1. manganese(II) sulfide A. CuS fill in the blank 2 2. calcium fluoride B. FeS C. PbCl2 D. CaCrO4 Write the expression for K in terms of the solubility, s, for each salt, when dissolved in water. manganese(II) sulfide calcium fluoride Ksp
Answer:
For each of the salts on the left, match the salts on the right that can be compared directly, using Ksp values, to estimate solubilities. (If more than one salt on the right can be directly compared, include all the relevant salts by writing your answer as a string of characters without punctuation, e.g, ABC.) fill in the blank 1 1. manganese(II) sulfide A. CuS fill in the blank 2 2. calcium fluoride B. FeS C. PbCl2 D. CaCrO4 Write the expression for K in terms of the solubility, s, for each salt, when dissolved in water. manganese(II) sulfide calcium fluoride Ksp
A 250ml sample of sir at 373.15k is warmed at 473.15 at constant pressure. What is the volume of the air sample at the new temperature
Answer:
317 mL.
Explanation:
From the question given above, the following data were obtained:
Initial volume (V₁) = 250 mL
Initial temperature (T₁) = 373.15 K
Final temperature (T₂) = 473.15 K
Pressure = Constant
Final volume (V₂) =?
The final volume of the air sample can be obtained by using the Charles' law equation as illustrated below:
V₁/T₁ = V₂/T₂
250 / 373.15 = V₂ / 473.15
Cross multiply
373.15 × V₂ = 250 × 473.15
373.15 × V₂ = 118287.5
Divide both side by 373.15
V₂ = 118287.5 / 373.15
V₂ = 317 mL
Therefore, the final volume of the air sample is 317 mL
An 11.5 mL portion of 0.162 M H3PO4 (aq) is to be titrated with 0.229 M NaOH (aq). What volume (in mL) of NaOH will it take to reach the equivalence point
Answer:
8.14 mL of NaOH are required to reach the equivalence point.
Explanation:
Formula for titration is
mmoles of base = mmoles of acid.
Equality is fullfilled at the equivalence point.
M of acid . volume of acid = M of base . volume of base
Let's replace with data given:
11.5 mL . 0.162M = 0.229 M . volume of base
Volume of base = (11.5 mL . 0.162M ) / 0.229M
Volume of base = 8.14 mL
8.14 mL of NaOH are required to reach the equivalence point.
Determine the electron geometry, molecular geometry, and idealized bond angles for each of the following molecules. CF4CF4 NF3NF3 OF2OF2 H2SH2S In which cases do you expect deviations from the idealized bond angle
Answer:
CF4
Molecular geometry- tetrahedral
Electron geometry- tetrahedral
NF3
-molecular geometry - trigonal pyramidal
Electron geometry - tetrahedral
OF2
Molecular geometry - bent
Molecular geometry - tetrahedral
H2S
Molecular geometry- bent
Electron geometry - tetrahedral
Explanation:
According to Valence Shell Electron Pair Repulsion Theory, the shape of a molecule depends on the number of electron pairs on the valence shell of the central atom in the molecule.
For all the compounds listed, the central atom has four points of electron density. This correspond to a tetrahedra electron pair geometry. The presence of lone pairs on the central atom of OF2,NF3 and H2S accounts for the departure of the observed molecular geometry from the geometry and idealized bond angle predicted on the basis of the VSEPR theory.
write the formula two atom of iron and three atoms of oxygen
Answer:
Fe2O3 is the formula this is your correct answer
chemical properties of epoxide
Answer:
Epoxides, also called oxiranes, have a three-membered ring structure with one oxygen and two carbon atoms.
Epoxides can be formed from alkenes by reaction with peroxy acids (MCPBA for example).
Epoxides can be formed from halohydrin molecules by reaction with a base, which causes an intramolecular Williamson ether synthesis.
Explanation:
Epoxide, cyclic ether with a three-membered ring. The basic structure of an epoxide contains an oxygen atom attached to two adjacent carbon atoms of a hydrocarbon. The strain of the three-membered ring makes an epoxide much more reactive than a typical acyclic ether.
Answer:
sana makatulong stay safe po
ASAP!!!!! The data table below shows a person’s heart rate measured in beats per minute (bpm) at five different times in the beginning of a day. What causes the change in heart rate over time?
1. tired
2. increased activity
3. passing of time
4. forgetting to eat
An unknown element, X, has an atomic mass of 107.868 amu. The X-109 isotope (108.905 amu) is 48.16%. What is the amu of the other isotope (report final answer to the correct number of significant figures)
Answer:
106.905 amu is the mass of the other isotope
Explanation:
The atomic mass of an element is the sum of the masses of the isotopes multiplied by its abundance. The atomic mass of an element X with 2 isotopes is:
X = X-109*i + X-107*i
Where X is the atomic mass = 107.868 amu
X-109 = 108.905amu, i = 48.16% = 0.4816
X-107 = ?, i = 1-0.4816 = 0.5184
Replacing:
107.868amu = 108.905amu*0.4816 + X-107*0.5184
55.4194 = X-107*0.5184
106.905 = X-107
106.905 amu is the mass of the other isotopePlease Help !! This is an Earth science lab question.
Explain why erosion occurs on the outside of a meander and deposition on the inside of a meander.
Answer:
The sideways movement occurs because the maximum velocity of the stream shifts toward the outside of the bend, causing erosion of the outer bank. At the same time the reduced current at the inside of the meander results in the deposition of coarse sediment, especially sand
Calculate the amount of energy produced by the conversion of 50.0 kg of mass into energy. Use 3.00 x 108 m/s for the speed of light. Round to 3 significant digits.
Which setup will solve this problem?
Answer:
tanong mo sa teacher mo ok
Answer:
E = (50.0 kg)(3.00 x 108 m/s)2
Explanation:
Compound A has the formula C8H8. It reacts rapidly with acidic KMnO4 but reacts with only 1 equivalent of H2 over a palladium catalyst. On hydrogenation under conditions that reduce aromatic rings, A reacts with 4 equivalents of H2, and hydrocarbon B, C8H16, is produced. The reaction of A with KMnO4 gives CO2 and a carboxylic acid C, C7H6O2.
Required:
Draw the structure of compound B below.
Answer:
C8H16 (Ethylcyclohexane).
Explanation:
From the given information:
Compound A is an alkene because it interacts with 1 unit of hydrogen across a palladium catalyst.
Also, we are given another hint that:
Compound A needs 4 equivalence of H2 to hydrogenate under circumstances that decrease aromatic rings, indicating that it is a phenyl substituted alkene.
Compound A with formula C8H8 reacts instantly with KMnO4 to produce CO2, as well as carboxylic acid, points out that Compound acts as a terminal alkene.
Therefore, we can opine that compound A is a terminal phenyl substituted alkene whose formula = C8H8 (Styrene)
The diagrammatic expression of the compound can be seen below.
However, in the presence of the palladium catalyst, the reduction of Compound A with 4 units of hydrogen produces Compound B: C8H16 (Ethylcyclohexane).
sino may kuyang palaging nambibira
Write the molecular formula for the compound that exhibits a molecular ion at M+ = 112.0499. Assume that C, H, N, and O might be present, and use the exact masses below: Exact mass of carbon = 12.000 Exact mass of hydrogen = 1.0078 Exact mass of nitrogen = 14.003 Exact mass of oxygen = 15.995 (The order of atoms should be carbon, then hydrogen, then the others in alphabetical order. If there is more than one answer, just give one. ) Molecular formula:
Answer:
C₅H₈N₂O
Explanation:
The molecular formula denotes the various forms of atoms contained in a molecule at a particular fixed proportion.
The molecular ion M⁺ = 112.0499
and the exact mass values are given as follows:
C = 12.000
H = 1.0078
N = 14.003
O = 15.995
By assumption:
C = 12.000 × 5 = 60.0000
H = 1.0078 × 8 = 1.0078
N = 14.003 × 2 = 28.0060
O = 15.995 × 1 = 15.9950
= 112.0634
This is approximtely equal to 112.0499.
As such the Molecular formula for the compound = C₅H₈N₂O
