Answer:
C. K
i took this class before
Answer: The largest element is K
Explanation: As K has the largest radius among O,He and H
When the pH of a solution is 12.83, what is [H +]?
A 7.4 × 10 -12 M
B 9.7 10 -11 M
C 1.5 X 10 -13 M
D 12.8 x 10 -2 M
Answer:
B.9.710-11M
Explanation:
plss tell me if im wrongI need help with the practice question at the bottom. Thank you.
Explanation:
For this question, we apply the equation: Q = mCp AT Where m is the mass of the substance, Cp
is its specific heat capacity and AT is the
temperature change. Q = 896 x 0.45 x (5-94)
Q = -35884.8 Joules
So about -36 kilojoules of heat is released.
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g in the following three compounds(1,2,3) arrange their relative reactivity towards the reagent CH3Cl / AlCl3. Justify your order
Answer:
3 > 2> 1
Explanation:
Aromatic compounds undergo electrophilic substitution reaction with several electrophiles.
Some substituted benzenes are more reactive towards electrophilic aromatic substitution than unsubstituted benzene.
Certain groups of substituents increase the ease with which an aromatic compound undergoes aromatic substitution.
If we look at the compounds closely, we will notice that only toluene leads to easy reaction with CH3Cl / AlCl3. Thus is due to the +I inductive effect of -CH3 which stabilizes the negatively charged intermediate produced in the reaction.
What is the empirical formula of a compound that has a pseudoformula of C3.5H8?
Answer:
The ratio of carbon and hydrogen atoms = 3.5 : 8
= 7 : 16
Then,the empirical formula is C7H16
give one important characteristic of the particles of matter very sort answer give
Answer:
The important characteristics of the particles of matter are – They are very, very small. They have spaces between them. They are constantly moving.
Answer:
They are very very small
Observe as equações e de acordo com Brönsted-Lowry, os compostos destacados são, respectivamente
answer
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Element X has two naturally occurring isotopes, 35X and 36X . 35X has a percent natural abundance of 30%, while 36X has a percent natural abundance of 70%. What is the average atomic mass of element X
Answer:
= 35.7 amu
Explanation:
Isotopic fractional Wt Avg mass
mass (amu) abundance (= % / 100) = Isotopic mass X (= % / 100)
X-35 35 0.30 10.5 amu
X-36 36 0.70 25.2 amu
__________________________________________________________
Average Atomic Mass of Element X = ∑ Wt. Avg. Masses = 35.7 amu
What intermolecular force or bond is primarily responsible for the solubility of chlorine (Cl2) in water
The question is incomplete, the common question is;
What intermolecular attractive force is primarily responsible for the solubility of chlorine, Cl2, in water?
a. dipole - dipole
b. hydrogen bonding
c. dipole-induced dipole
d. ion-dipole
e. ion-induced dipole
Answer:
dipole-induced dipole
Explanation:
We have to remember that water is a polar molecule hence it possesses a dipole moment. Its dipole moment is responsible for the ability of water to dissolve many substances.
On the other hand, Cl2 is a nonpolar molecule bound together by only weak dispersion forces.
Recall that dispersion forces involve transient appearance of a dipole in a molecule.
Water molecules can induce a dipole in Cl2 thereby causing the both molecules to interact and Cl2 dissolves in water.
Which of the following is an alkaline earth metal?
O A. Carbon (C)
O B. Aluminum (AI)
O C. Magnesium (Mg)
O D. Silicon (Si)
Answer:
Magnesium (Mg)
Explanation:
The elements have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure.
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Answer:
The answer is C. Magnesium(Mg)
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why do people who do a lot of physical work need more carbohydrate?
Answer:
A person doing physical work needs lots of good carbohydrates to keep their energy levels up and proteins to repair a muscle that might get wear and tear from overexertion. Carbohydrate will help the person work for more extended periods.
Predict the products from reaction of 2-hexyne with the following reagents: (a) 2 equiv Br2 (b) 1 equiv HBr (c) Excess HBr (d) Li in NH3 (e) H2O, H2SO4, HgSO4
Answer:
See explanation and image attached
Explanation:
The reactions of the alkynes involved are shown in the image attached to this answer.
First of all, the reaction of two equivalents of bromine with the alkyne converts it to a saturated compound as shown. One equivalent of HBr converts the alkyne to alkene while excess HBr completely reduces the compound to a saturated compound.
Li/NH3 reduces the alkyne to an alkeneby anti addition to the triple bond.
Reaction of the alkyne with H2O, H2SO4, HgSO4 converts it to an aldehyde as shown.
the pressure of a sample of helium in a 0.150 L container is 1520 torr. if the helium is compressed to the volume of 0.012 L without changing the temperature what would be the pressure of the gas
Answer:
19000 torr
Explanation:
From the question given above, the following data were obtained:
Initial volume (V₁) = 0.150 L
Initial pressure (P₁) = 1520 torr
Final volume (V₂) = 0.012 L
Temperature = constant
Final pressure (P₂) =?
The final pressure of the gas can be obtained by using the Boyle's law equation as illustrated below:
P₁V₁ = P₂V₂
1520 × 0.150 = P₂ × 0.012
228 = P₂ × 0.012
Divide both side by 0.012
P₂ = 228 / 0.012
P₂ = 19000 torr
Thus, the final pressure of the gas is 19000 torr
Draw bond-line formulas of all dichloro derivatives that might be formed when 1-chloro-2,2,3,3,-tetramethylpentane is allowed to react with Cl 2 under UV irradiation. For each structure, indicate, with an asterisk, any stereocenters that might be present. Predcit the percentage of each product using the relative reactivities 3 0 = 5.3, 2 0 = 3.6, 1 0 = 1
Answer:
Explanation:
This is a halogenation reaction i.e substitution or replacement of a single or more than a single hydrogen atom in the organic alkane compound with the halogen(here it is chlorine).
The chlorination of 1-chloro-2,2,3,3-tetramethylpentane under UV light resulted in the formation of five (5) dichloro derivatives which are shown in the image attached below.
Also, the compounds containing a stereocenter (i.e a location within the compound composing of various substituents in which the interchangeability of these substituents has the tendency of resulting into a stereoisomer) are indicated with an asterisk in the image below.
From the image below:
compound 1 ⇒ 1,1-dichloro-2,2,3,3-tetramethylpentane = 2° C
∴
The given relative reactivity rate for 2° = 3.6x
For compound 2 ⇒ 1,4-dichloro-2,2,3,3-tetramethylpentane = 2° = 3.6x
For compound 3 ⇒ 1,5-dichloro-2,2,3,3-tetramethylpentane = 1° = 1x
For compound 4 ⇒ 1-chloro-2-chloromethyl-2,3,3-trimethylpentane
= 1° = 1x
For compound 5 ⇒ 1-chloro-3-chloromethyl-2,2,3-trimethylpentane
= 1° = 1x
As such, we have:
2(3.6x) + 3(1x) = 100
7.2x + 3x = 100
10.2x = 100
x = 100/10.2
x = 9.803°
∴
For compound (1) = 3.6(9.803) = 35.3%
For compound (2) = 3.6(9.803) = 35.3%
For compound (3) = 1(9.803) = 9.803°%
For compound (4) = 1(9.803) = 9.803°%
For compound (5) = 1(9.803) = 9.803°%
Suppose you need to prepare 138.1 mL of a 0.190 M aqueous solution of NaCl. What mass, in grams, of NaCl do you need to use to make the solution
Answer:
Explanation:
· 44 g NaCl Explanation: The problem provides you with the molarity and volume of the target
The answer is rounded to two sig figs, the number of sig figs you have for the molarity of the solution.
The mass of a solute needed to prepare a solution with given volume is find by molarity. The mass of NaCl need to make a 138.1 mL solution of 0.190 M is 1.53 grams.
What is molarity ?Molarity of a solution is a term to express its concentration. Mathematically, it is the ratio of no.of moles of solute to the volume of solution in litres.
Given that, the volume of solution is 138.1 mL. One litre solution is 1000 mL. Hence, 138.1 mL is 0.1381 L. The molarity of the solution is 0.190 M. From these data we can calculate the no.of moles of NaCl as below:
no.of moles = molarity × volume of solution in L
= 0.190 M × 0.1381 L
= 0.0262 moles.
This is the no.of moles required to make the solution.
Molecular mass of NaCl = 58.4 g/mol.
Thus mass of 0.0262 moles of NaCl = 0.0262 mol × 58.4 g/mol
= 1.53 g.
Therefore, the mass of NaCl required is 1.53 g.
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An atom has 6 protons and 9 neutrons in its nucleus. Calculate the mass number of the atom
Answer:
6+9=15
mass number =15
mass number = no. protons + no. of neutrons
When 2.50 moles of oxygen reacts with excess hydrogen gas how many grams of water is
produced?
2 H2 + O2--> 2 H20
Answer:
90grams
Explanation:
The reaction given in this question is as follows:
2H2 + O2 → 2H20
Based on this equation, 1 mole of oxygen gas (O2) produces 2 moles of water (H2O)
Hence, 2.50moles of oxygen gas will react with excess hydrogen gas to produce (2.5 × 2) = 5.0moles of water.
Using mole = mass/molar mass
Molar mass of water (H2O) = 1(2) + 16
= 18g/mol
5 = mass/18
mass = 18 × 5
mass of H2O = 90grams
How many molecules make up 12.8g of N2O4
Answer:
8.35 × 10 ²² molecules
Explanation:
gram molecular weight of N2O4
= 2 × 14 + 4 × 16
= 28 + 64
= 92g
1 mole N2O4 has 6 × 10²³ molecules of N2O4 and weighs 92g
therfore,
92 g has = 6 × 10²³ molecules
12.8 g has =
[tex] \frac{6 \times 10 {}^{23}}{92} \times 12.8[/tex]
= 0.835 × 10²³
= 8.35 × 10 ²² molecules
Essentially all of the mass of an atom is due to the?
nucleons
electrons.
protons
Neutrons
Answer:
nucleons
Explanation:
The answer to the question is nucleons. Because there are both protons and neutrons in the nucleon, it will be heavier. Also, protons and neutrons are much heavier than the weight of an electron, because electrons float around the atom so it is not the answer. So, our final answer is actually option A.
Name two natural sources of esters.
Answer:
"Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits, including apples, durians, pears, bananas, pineapples, and strawberries."
Explanation:
11
Na
Sodium
22.99
What does 22.99 stand for
Explain carefully what happen to the propanol-water system if approximately
50% of propanol by mass is fractionally distilled. What will be the distillate and
the residue?
Answer:
In the case of mixtures of ethanol and water, this minimum occurs with 95.6% by mass of ethanol in the mixture. The boiling point of this mixture is 78.2°C, compared with the boiling point of pure ethanol at 78.5°C, and water at 100°C. You might think that this 0.3°C doesn't matter much, but it has huge implications for the separation of ethanol / water mixtures. The next diagram shows the boiling point / composition curve for ethanol / water mixtures. I've also included on the same diagram a vapor composition curve in exactly the same way as we looked at on the previous pages about phase diagrams for ideal mixtures.
1. What is the equivalent pressure measurement in mmHg of 2.50 atm?
Answer:
Atmosphere to mmHg Conversion Example. Task: Convert 8 atmospheres to mmHg (show work) Formula: atm x 760 = mmHg Calculations: 8 atm x 760 = 6,080 mmHg Result: 8 atm is equal to 6,080 mmHg.
Explanation:
This answer is helpfull for you I nowA physical chemist measures the temperature inside a vacuum chamber. Here is the result.
T= - 35.903°C
Convert T to SI units.
This is an acronym of the word Systeme International in French. Its International System of Units (SI) is a metric system that would be universally acknowledged as a measurement standard, and the further discussion can be defined as follows:
SI units play an important function in research and innovation in science and technology. In this, the temperature will be measure in the kelvin.Conversion [tex]^{\circ} \ to \ K[/tex]:
let,
[tex]\to 0^{\circ}\ C + 273.15 = 273.15\ K\\\\[/tex]
So,
[tex]\to -35.903+273.15=237.247\ K[/tex]
Therefore, the final answer is "237.247".
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g You observed the formation of several precipitates in the Reactions in Solution lab exercise. Identify the precipitate in each of the following reactions: a. The yellow precipitate formed in the reaction between KI and Pb(NO3)2 is . b. The white precipitate formed in the reaction between BaCl2 and H2SO4 is . c. The brown precipitate formed in the reaction between NaOH and FeCl3 is . d. The blue precipitate formed in the reaction between CuSO4 and NaOH is .
Answer:
For a: Lead iodide is a yellow precipitate.
For b: Barium sulfate is a white precipitate.
For c: Ferric hydroxide is a brown precipitate.
For d: Copper (II) hydroxide is a blue precipitate.
Explanation:
Precipitation reaction is defined as the reaction where a solid precipitate (solid substance) is formed at the end of the reaction. It is insoluble in water.
For the given options:
For (a):The chemical reaction between KI and lead (II) nitrate follows:
[tex]2KI(aq)+Pb(NO_3)_2(aq)\rightarrow PbI_2(s)+2KNO_3(aq)[/tex]
The iodide of lead is generally insoluble in water. Thus, lead iodide is a yellow precipitate.
For b:The chemical reaction between barium chloride and sulfuric acid follows:
[tex]BaCl_2(aq)+H_2SO_4(aq)\rightarrow BaSO_4(s)+2HCl(aq)[/tex]
The sulfate of barium is insoluble in water. Thus, barium sulfate is a white precipitate.
For c:The chemical reaction between NaOH and ferric chloride follows:
[tex]3NaOH(aq)+FeCl_3(aq)\rightarrow Fe(OH)_3(s)+3NaCl(aq)[/tex]
The hydroxide of iron is insoluble in water. Thus, ferric hydroxide is a brown precipitate.
For d:The chemical reaction between NaOH and copper sulfate follows:
[tex]CuSO_4+2NaOH\rightarrow Cu(OH)_2+Na_2SO_4[/tex]
The hydroxide of copper is insoluble in water. Thus, copper (II) hydroxide is a blue precipitate.
(a) The yellow precipitate formed in the reaction between KI and Pb(NO3)2 would be PbI2 according to the equation:
[tex]Pb(NO_3)_2(aq) + 2KI(aq) ---> PbI2(s) + 2KNO_3(aq)[/tex]
(b) The white precipitate formed in the reaction between BaCl2 and H2SO4 would be BaSO4 according to the equation:
[tex]BaCl_2 (aq) + H_2SO_4 (aq) ---> BaSO_4 (s) + 2 HCl (aq)[/tex]
(c) The brown precipitate formed in the reaction between NaOH and FeCl3 would be Fe(OH)3 according to the equation:
[tex]FeCl_3 (aq) + NaOH (aq) ---> Fe(OH)_3 (s) + NaCl (aq)[/tex]
(d) The blue precipitate formed in the reaction between CuSO4 and NaOH would be Cu(OH)2 according to the equation:
[tex]CuSO_4(aq) + 2 NaOH (aq) ---> Cu(OH)_2 (s) + Na_2SO_4 (aq)[/tex]
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The molar mass of a compound can be determined by the freezing point depression method. The solution must be relatively dilute and you must know the molal freezing point depression constant of the solvent, Kf. Which statement regarding Kf is true?
A. Kf should be small so that the solvent will not sublimate.
B. Kf will change depending on what solute is dissolved in the solvent.
C. Kf should be negative so the freezing point of the solution will decrease.
D. Kf should be large so the temperature change will be large enough to measure.
Answer:
K should be large so the temperature change will be large enough to measure.
Explanation:
Let us recall that;
∆T = k m I
Where;
∆T= change in boiling point
K= freezing point constant
m= molality
i= Van't Hoff factor
Since the change in temperature depends on k, the larger the value of k the larger the temperature change(Ts - Tb). Hence; K should be large so the temperature change will be large enough to measure.
Ts= freezing temperature of pure solvent
Tb= freezing temperature of solution
or each conjugate acid-base pair, identify the first species as an acid or base and the second species as the conjugate acid or base of the first. A) CH3COOH and B) CH3COO- A. is _____ B. is _________ C) CH3O- and D) CH3OH C. is _____ D. is _________
Answer:
A. an acid
B. a base
C. conjugate base
D. conjugate acid
Explanation:
This question appears incomplete because it is starting with a "or".
However, the available question can still be answered.
An acid (according to "Bronsted-Lowry") is a chemical compound/specie that can donate hydrogen ion(s) in a reaction while a base is the compound/specie that can receive hydrogen ion(s). From this definition, it can be deduced that CH₃COOH (ethanoic acid) is an acid (weak acid) because it can donate an hydrogen ion while CH₃COO⁻ is a base because it can receive a hydrogen ion.
Also, a conjugate acid is the compound formed when an acid has donated a hydrogen ion to a base (i.e it is a base with hydrogen ion attached to it) while a conjugate base is the acid that has lost it's hydrogen ion. Thus, the conjugate acid in the question is CH₃OH while the conjugate base in the question is CH₃O⁻.
A. an acid
B. a base
C. conjugate base
D. conjugate acid
NaCl is ___ formula of common salt
A. Empirical formula
B. Molecular formula
C. Both A and B
D. None of them
What molecule is this
Answer:
That is a " ball and stick " model which represents carbon compounds.
Explanation:
This is the answer. Hope it helps you find what you're looking for.
Energy Changes in Reactions
Independent Practice
In a synthesis reaction, one reactant contains 256 J of chemical energy, and one reactant contains 328 J of
chemical energy. The product contains 407 J of chemical energy.
Because energy is conserved, what energy change occurs during the reaction?
A. 177 J of energy is released.
B. 177 J of energy is absorbed.
C. 335 J of energy is released,
D. 335 J of energy is absorbed.
SAVE
SAVE AND CLOSE
Which observation provided Albert Einstein the clue that he needed to explain the photoelectric effect?
Answer:
Einstein realized that the energy in electrons was caused by the frequency of light and not the intensity of light. This made him realize that he needed to explain the photoelectric effect.
Explanation:
Einstein realized that the photoelectric effect was a system that should be studied and explained in more depth, when he saw how the energy of electrons behaved in the presence of light. He saw that this energy depends entirely on the frequency of light and not on the intensity of light. From this observation, he realized that the photoelectric effect was essential for the production of an electric energy system, through light energy, such as solar energy.
It is important to note that the photoelectric effect refers to the ejection of electrons on a light surface that comes into contact with a light source.
