Explanation:
If there are 15 protons, 15 nuclear particles of unit positive charge, then
Z
=
15
. Now
Z
≡
the atomic number
, and you look at your copy of the Periodic Table, and you find that for
Z
=
15
, the element phosphorus is specified.
But we are not finished. Along with the 15 defining protons, there are also 16 neutrally charged, massive nuclear particles, 16 neutrons, and the protons and neutrons together determine the atomic mass. The isotope is thus
31
P
, which is almost 100% abundant, and an important nucleus for
NMR spectroscopy.
Why is iodine always Used in a solution containing excess I2
Answer:
If a standard iodine solution is used as a titrant for an oxidizable analyte, the technique is iodimetry. If an excess of iodide is used to reduce a chemical species while simultaneously forming iodine.
Iodine always used in a solution excess KI is given to aid in the solubilization of free iodine, which would be insoluble in clean water during normal circumstances.
What is Iodine?
Iodine is a kind of element which are mainly used in iodometry titration. It can be represented by I.
What is solution?A solution would be a homogenous mixture of two components, usually a solute as well as a solvent.
Iodimetry would be a technique that uses a standard iodine solution as a titrant for such an oxidizable analyte. When an excessive amount of iodide is used to decrease a chemical while somehow producing iodine.
To know more about iodine and solution
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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
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
2KClO3 (s)⇄2KCl (s)+ 3O2 (aq) equilibrium constant
Answer: The equilibrium constant for the given chemical reaction is [tex][O_2]^3[/tex]
Explanation:
The equilibrium constant is defined as the ratio of the concentration of the products to the concentration of reactants each raised to the power of their stoichiometric coefficients.
The concentration of all the solids and liquids are considered to be 1 in the expression of equilibrium constant
For the given chemical equation:
[tex]2KClO_3(s)\rightleftharpoons 2KCl(s)+3O_2(aq)[/tex]
The expression of equilibrium constant follows:
[tex]K_{eq}=[O_2]^3[/tex]
Hence, the equilibrium constant for the given chemical reaction is [tex][O_2]^3[/tex]
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:
The limiting reactant in a chemical reaction is the reactant __________ Select one: A. for which you have the lowest mass in grams. B. which has the lowest coefficient in the balanced equation. C. which has the lowest molar mass. D. which is left over after the reaction has gone to completion. E. None of the above.
Answer:
i think its A
If 0.5 L of O2(g) reacts with H, to produce 1 L of H2O(g), what is the volume of
H2O(g) obtained from 1 L of O2(g)?
-
0.5 L
2.5 L
2 L
1.5 L
Answer:
2 L
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
2H₂ + O₂ —> 2H₂O
From the balanced equation above, we can see clearly that 1 L of O₂ reacted to 2 L of H₂O.
This implies that 2 L of H₂O can be obtained by the reaction of 1 L of O₂.
Thus, option 3 gives the correct answer to the question.
How many grams of Al2O3 is extracted from 250. g of FeO?
Answer:
[tex]m_{Al_2O_3}=118.27gAl_2O_3[/tex]
Explanation:
Hello there!
In this case, if we consider the following chemical reaction, whereby Al2O3 is produced from Al and FeO:
[tex]3FeO+2Al\rightarrow 3Fe+Al_2O_3[/tex]
Thus, since there is 3:1 mole ratio of FeO to Al2O3, it turns out feasible for us to use their molar masses, 71.844 g/mol and 101.96 g/mol respectively, to obtain the grams of the latter as follows:
[tex]m_{Al_2O_3}=250.gFeO*\frac{1molFeO}{71.844gFeO}*\frac{1molAl_2O_3}{3molFeO} *\frac{101.96gAl_2O_3}{1molAl_2O_3}\\\\m_{Al_2O_3}=118.27gAl_2O_3[/tex]
Regards!
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 climate zone is asia?
Answer:
The Tundra Climate
Explanation:
:) hope this helps
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).
A 15.0 mL urine from a dehydrated patient has a density of 1.019g/mL. What is the mass of the sample, reported in mg?
Answer:
Mass of sample in mg = 15,285 mg
Explanation:
Given:
Volume of urine sample = 15 ml
Density of sample = 1.019 g/ml
FInd:
Mass of sample in mg
Computation:
Mass = density x volume
Mass of sample in mg = Volume of urine sample x Density of sample
Mass of sample in mg = 1.019 x 15
Mass of sample in mg = 15.285 gram
Mass of sample in mg = 15.285 x 1,000
Mass of sample in mg = 15,285 mg
Use the following information to calculate the concentration, Ka and pka for an unknown monoprotic weak acid. (8 pts.) 20.00 mL
Volume of unknown weak acid used : 20.00 mL Total volume of 0.20 M NaOH required to reach the equivalence point: 18.50 mL Initial pH of the weak acid 2.87
Answer:
Concentration: 0.185M HX
Ka = 9.836x10⁻⁶
pKa = 5.01
Explanation:
A weak acid, HX, reacts with NaOH as follows:
HX + NaOH → NaX + H2O
Where 1 mole of HX reacts with 1 mole of NaOH
To solve this question we need to find the moles of NaOH at equivalence point (Were moles HX = Moles NaOH).
18.50mL = 0.01850L * (0.20mol / L) = 0.00370 moles NaOH = Moles HX
In 20.0mL = 0.0200L =
0.00370 moles HX / 0.0200L = 0.185M HX
The equilibrium of HX is:
HX(aq) ⇄ H⁺(aq) + X⁻(aq)
And Ka is defined as:
Ka = [H⁺] [X⁻] / [HX]
Where [H⁺] = [X⁻] because comes from the same equilibrium
As pH = 2.87, [H+] = 10^-pH = 1.349x10⁻³M
Replacing:
Ka = [H⁺] [H⁺] / [HX]
Ka = [1.349x10⁻³M]² / [0.185M]
Ka = 9.836x10⁻⁶
pKa = -log Ka
pKa = 5.01Write 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
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
As a result of the particles in a gas being in constant motion, gas has a _______.
variable volume
variable Pressure
variable Shape
variable mass
Answer:
i think it's variable pressure
if not soo advance sorry :)
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
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.
write the formula two atom of iron and three atoms of oxygen
Answer:
Fe2O3 is the formula this is your correct answer
A molecule of composition is replicated in a solution containing unlabeled (not radioactive) GTP, CTP, and TTP plus adenine nucleoside triphosphate with all its phosphorus atoms in the form of the radioactive isotope 32P. Will both daughter molecules be radioactive
Answer:
Please find the complete question in the attached file.
Explanation:
It would only be radioactive if the DNA molecule that employed the poly-T rand as templates. Its other molecule of the daughter would not have been radioactive as it did not need dATP for its replication. While each strand of the second molecule includes t, simultaneous reproduction dATP from both daughter molecules is needed so that each of those is radioactive.
Which commercial technology commonly uses plasmas?
a radio
a race car
a television
a microwave oven
Answer:
A television is commercial technology commonly uses plasmas.Calculate the mass of hydrogen formed when 26.98 g of aluminum reacts with excess hydrochloric acid according to the following balanced chemical equation: 2 Al + 6 HCl → 2 AlCl3 + 3 H2
Answer: The mass of hydrogen formed when 26.98 g of aluminum reacts with excess hydrochloric acid according to the given balanced equation is 3.03 g.
Explanation:
The given balanced reaction equation is as follows.
[tex]2Al + 6HCl \rightarrow 2AlCl_{3} + 3H_{2}[/tex]
Here, the mole ration of Al and hydrogen produced is 2 : 3
As mass of aluminum is given as 26.98 g. So, moles of aluminum (molar mass = 26.98 g/mol) is as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{26.98 g}{26.98 g/mol}\\= 1 mol[/tex]
So, when 1 mole of Al reacted then 1.5 moles of hydrogen is produced as per the given mole ratio.
Therefore, mass of hydrogen formed is calculated as follows.
[tex]mass = moles \times molar mass\\= 1.5 mol \times 2.02 g/mol\\= 3.03 g[/tex]
Thus, we can conclude that the mass of hydrogen formed when 26.98 g of aluminum reacts with excess hydrochloric acid according to the given balanced equation is 3.03 g.
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.
How much energy does an X-ray with an 8 nm (8 x 10-9m) wavelength have?
A. 1.99 x 10-25 J
B. 3.33 x 1016 J
C. 2.48 x 10-17 j
D. 8.28 x 10-26 J
Answer:
it would be option C
Explanation:
Speed of light = 3×10^8m/s
Planck's constant = 6.626×10^-34 Js
Wavelength = 8 x 10^-9 m
Energy = [(3×10^8) * (6.626×10^-34)] / 8 x 10^-9
Energy = [19.878×10^(8-34)] / 8 x 10^-9
Energy = 2.48475 × 10^(-26+9)
Energy = 2.48×10^-17 J
Given the balanced reaction: Zn + 2HCl → H2 + ZnCl2
If 5 grams of each reactant are available for the reaction and HCl is known
to be the limiting reactant, which of the following is correct?
O Both reactants will be completely used up.
O There will be excess of both reactants remaining.
O HCl will be completely used up while Zn will remain in excess.
O Zn will be completely used up while HCl will remain in excess.
Answer:
O HCl will be completely used up while Zn will remain in excess.
Explanation:
Zn + 2HCl → H₂ + ZnCl₂In reactions involving two reactants, if one of them is the limiting reactant then the other one has to be the reactant in excess.
Meaning that in this case, the reaction will proceed until HCl is completely used up, and a certain amount of Zn will remain (thus being the reactant in excess).
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 isotopeA transition metal in the fourth period from the following list : Cu, O , Pr, Ag
Answer:
Cu
Explanation:
Groups 3 - 12 (or groups IIA - IIB) of the periodic table contain transition elements. Transaction elements start from period four (4) of the periodic table. The phrase alludes to the fact that the d sublevel is filling at a lower main energy level than the s sublevel that came before it.
The transition elements' arrangement is inverted from the fill order, with the 4 s filled prior to the actual 3 d begins. The transition elements are commonly referred to as transition metals since they are all metals. They are less reactive than the metals in Groups 1 and 2 and have normal metallic characteristics.
From the options given Cu is the only transition metal in the fourth period on the periodic table.
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
is it a physical or chemical change when a candle is lit
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
