Answer:
B
Explanation:
hợp chất nào có khả năng là hợp chất ion cao nhất ?
A Al2O3?
B
Draw the Lewis structure of NCl3NCl3 . Include lone pairs. Select Draw Rings More Erase Select Draw Rings More Erase Select Draw Rings More Erase Select Draw Rings More Erase Select Draw Rings More Erase Select Draw Rings More Erase Select Draw Rings More Erase Select Draw Rings More Erase Select Draw Rings More Erase Select Draw Rings More Erase Select Draw Rings More Erase Cl N
Answer:
See explanation and image attached
Explanation:
Nitrogen trichloride NCl3 contains one nitrogen and three chlorine atoms. Each chlorine atom has three lone pairs of electrons while nitrogen has one lone pair of electrons.
The molecule geometry of the molecule is trigonal pyramidal while it's electron domain geometry is tetrahedral. Nitrogen is the central atom and is found in sp3 hybridization.
There is no formal charge on the molecule.
(NH4)2SO4(aq)+SrCl2(aq)→
What is the initial pressure of a gas if it’s occupied a volume of 0.375 L but now occupies a volume of 1.25 L at a pressure of 95.5 K PA
Answer:
318 kPa
Explanation:
Step 1: Given data
Initial pressure (P₁): ?Initial volume (V₁): 0.375 LFinal pressure (P₂): 95.5 kPaFinal volume (V₂): 1.25 LStep 2: Calculate the initial pressure of the gas
Assuming constant temperature and ideal behavior, we can calculate the initial pressure of the gas using Boyle's law.
P₁ × V₁ = P₂ × V₂
P₁ = P₂ × V₂ / V₁
P₁ = 95.5 kPa × 1.25 L / 0.375 L = 318 kPa
The literature values listed for the unknowns in this assignment are from either the Merck Index or the CRC Handbook, the two most used reference handbooks. However, the values tend to vary slightly across literature sources and sometimes the temperatures are given as ranges. Give at least one reason for the variations in these reported temperatures.
In general, the boiling points of compounds increase down a group in the periodic table. The melting points and boiling points for the hydrogen compounds of group 6A elements are in the table below.
Melting point (0C) Boiling point (oC)
H2O 0.0 100.0
H2S -82.0 -60.0
H2Se -65.7 -41.2
H2Te -49.0 -2.2
Answer:
See explanation
Explanation:
One of the important trends in the periodic table is electronegativity. Electro negativity decreases down the group and increases across the period. This trend has important consequences on the observed properties of the compounds of elements in a particular group in the periodic table.
As we move down in group 6A, the electro negativity of the elements elements the group decrease and as such, the magnitude of intermolecular hydrogen bonding between the molecules also decrease accordingly. Hydrogen bonds occur between
molecules of a substance when hydrogen is covalently bonded to an electronegative element. Hydrogen bonding is responsible for the high melting and boiling points of small molecules such as water which contain the highly electronegative oxygen atom.
So, as we move down the group there is lesser intermolecular hydrogen bonding between the hydride molecules of group 6A elements resulting in the observed trend in melting and boiling points of the hydrides.
The weaker hydrogen bonds that occurbetween molecules of group 6A hydrides lead to a steady decrease in melting and boiling points of the hydrides of group 6A elements as we move down the group.
Which state of matter is characterized by having an indefinite shape, but a definite volume?
solid
gas
liquid
Answer:
liquid is the right answer k
Answer:
liquid
Explanation:
Select the correct answer.
What is the solution to the problem expressed to the correct number of significant figures?
(102,900 ÷ 12) + (170 × 1.27) = ?
One of the nuclides in spent nuclear fuel is U-235, an alpha emitter with a half-life of 703 million years. How long will it take for an amount of U-235 to reach 23.0% of its initial amount
Answer:
1.49 × 10⁹ years
Explanation:
Step 1: Calculate the rate constant (k) for the nuclear decay of U-235
The decay follows first-order kinetics with a half-life (t1/2) of 703 × 10⁶ years. We can calculate "k" using the following expression.
k = ln2/ t1/2 = ln2 / 703 × 10⁶ y = 9.86 × 10⁻¹⁰ y⁻¹
Step 2: Calculate the time elapsed (t) so that the final amount ([U]) is 23.0% of the initial amount ([U]₀)
For first order kinetics, we will use the following expression.
ln ([U]/[U]₀) = -k × t
ln (0.230[U]₀/[U]₀) = -9.86 × 10⁻¹⁰ y⁻¹ × t
ln 0.230 = -9.86 × 10⁻¹⁰ y⁻¹ × t
t = 1.49 × 10⁹ y
Suppose an element has two naturally occurring isotopes
42
X
20
44
X
20
with atomic masses 42.00 amu and 45.00 amu, respectively. Determine the percent abundance of the
45
X
20
isotope given an average atomic mass of 43.22 amu.
Answer:
Chlorine
Chlorine has two naturally occurring isotopes. In a sample of chlorine, 75.77% of the atoms are Cl-35, with a mass of 34.97amu.
Explanation:
hope it helps thanks❤
Chlorine has two naturally occurring isotopes. In a sample of chlorine, 75.77% of the atoms are Cl-35, with a mass of 34.97amu.
How do you calculate the atomic mass in percentage by isotopes?
List the known and unknown values and edit the problem. Convert each percentage value into a decimal by dividing it by 100. Multiply this number by the atomic mass of that spot. Mix together each isotope to find the median atomic mass.
How do you get the maximum amount of two isotopes?To calculate the maximum percentage of each isotope in a sample of something, chemists usually divide the atomic number of a particular isotope by the total number of atoms of all that isotope and multiply the result by 100.
Learn more about isotopes here: brainly.com/question/6258301
#SPJ2
what is the atomic structure of an element that has atomic number of 11 and neutron number of 12.
Answer:
See explanation
Explanation:
The atomic number refers to the number of protons in the nucleus, it also tells us the number of electrons in the neutral atom since the atom is electrically neutral because the number of protons and electrons are equal.
If an atom has the atomic number 11, then the electrons in the atom are arranged in the shells in the order; 2, 8, 1.
Two electrons are found in the innermost shell, eight electrons are found in the next shell and one electron is found on the outermost shell.
The nucleus of the atom is composed of a total of 23 nucleons; 11 protons and 12 neutrons.
Which best illustrates the way in which radiation transfers thermal energy?
O
Warr
Cool
o
Warm
Cool
Warm
Cool
Warm
H11
Cool
Answer:
It is so because heat is flowing from hot body to cold body, and there is no direct contact between the body. It explains correctly the mode of transmission of thermal energy through the process of radiations.
Explanation:
Fun fact:
How does thermal energy transfer by radiation?
Radiation. All objects transfer energy to their surroundings by infrared radiation . The hotter an object is, the more infrared radiation it gives off. No particles are involved in radiation, unlike conduction.
g Ions B and C react to form the complex BC. If 35.0 mL of 1.00 M B is combined with 35.0 mL of 1.00 M C, 0.00500 mol of BC is formed. Determine the equilibrium constant for this reaction.
Answer:
Kf = 0.389.
Explanation:
Hello there!
In this case, it turns out possible for us to solve this problem by firstly writing the equilibrium chemical equation and equilibrium expression for the formation of this complex:
[tex]B+C\rightleftharpoons BC\\\\Kf=\frac{[BC]}{[B][C]}[/tex]
Thus, we firstly calculate the concentrations at equilibrium, knowing that the reaction extent in this case is 0.00500mol (same as the formed moles of BC):
[tex][B]=[C]=\frac{0.0350L*1.00mol/L-0.00500mol}{0.0700L} =0.429M[/tex]
[tex][BC]=\frac{0.00500mol}{0.0700L} =0.0714M[/tex]
And finally, the equilibrium constant:
[tex]Kf=\frac{0.0714}{[0.429][0.429]}\\\\Kf=0.389[/tex]
Regards!
1. As you go across a period, what is a useful comparison point?
A.
oxides
B.
halides
C.
hydrides
D.
hydroxides
-----
2. Most elements are
A.
allotropes
B.
nonmetals
C.
metalloids
D.
metals
----
3. A metalloid is a(n) __ conductor of heat and electricity than a metal.
A.
better
B.
worse
C.
equal
D.
cannot be determined
-----
4. What causes the formation of allotropes?
A.
pressure
B.
light
C.
temperature
D.
all of the above
----
As you move __and __ elements become more metallic.
A.
left, down
B.
right, down
C.
right, up
D.
left, up
------
5. All of the following metalloids form allotropes except
A.
B
B.
Si
C.
Te
D.
Po
------
6. What is a chemical property of a metal?
A.
malleable
B.
ductile
C.
positive oxidation states
D.
conducts heat and electricity
----
Explanation:
1. As you go across a period, what is a useful comparison point?
A.
oxides
2. Most elements are
A.
allotropes
3. A metalloid is a(n) __ conductor of heat and electricity than a metal.
A.
better
4. What causes the formation of allotropes?
A.
pressure
As you move __and __ elements become more metallic.
A.
left, down
5. All of the following metalloids form allotropes except
A.
B
6. What is a chemical property of a metal?
A.
malleable
A 2.9 kg model rocket accelerates at 15.3 m/s2 with a force of 44 N. Before launch, the model rocket was not moving. After the solid rocket engine ignited, hot gases were pushed out from the rocket engine nozzle and propelled the rocket toward the sky.
Which of Newton’s laws apply in this example?
Answer:
Newton's first and third law of Motion
Explanation:
The laws applying in the example Newton's first and third laws of Motion.
The first law states that any object at rest (ie. not moving) will stay at rest until it is forced to move by an external force. In this case, said force were the propulsion gases ignited.As the hot gases were pushed out from the engine nozzle, there was another force equal in magnitud but opposite in direction (as the gases went down, that force went upwards), said force is directly responsible for the rocket taking off. That is an example of the third law.Answer:
It Newtons first, second, and third laws
Explanation:
What does the rate law tell you about a reaction?
A. How the concentration of the reactants affects the rate of a
reaction
B. How temperature affects the rate of a reaction
C. How the equilibrium constant is related to the rate of a reaction
D. How the rate of a reaction affects the total time of a reaction
Answer:
A. How the concentration of the reactants affects the rate of a reaction
Explanation:
Let's consider a generic reaction.
A + B ⇒ Products
The generic rate law is:
rate = k × [A]ᵃ × [B]ᵇ
where,
rate: rate of the reaction[A] and [B]: molar concentrations of the reactantsk: rate constanta and b: reaction ordersAs we can see, the rate law shows how the concentration of the reactants affects the rate of a reaction.
The "nitrogen rule" of mass spectrometry requires a compound containing an odd number of nitrogens to have an odd-mass molecular ion and a compound containing an even number of nitrogens to have an even-mass molecular ion. What is the molecular formula of the CHN-containing compound pyrazine, M+ = 80? (The order of atoms should be carbon, then hydrogen, then others in alphabetical order.)
Answer:
C₄H₄N₂
Explanation:
Given that:
M+ = 80.
It implies that the number of nitrogen present in the molecule must also be even according to the Nitrogen rule.
So from the Formula CHN, the nitrogen will have to be 2 because if we make use of 4, it will exceed the given M+ which is 80.
∴
C₄ = 4 × 12 = 48
H₄ = 4 × 1 = 4
N₂ = 2 × 14 = 28
80
As such, the molecular formula of the compound is C₄H₄N₂
____________ can increase the presence of 5HT in the terminal button or synaptic cleft.
Answer:
Selective serotonin reuptake inhibitors (SSRIs)
Explanation:
A synaptic cleft is a space that separates two neurons thereby forming a junction between two or more neurons. The synaptic cleft helps in the transfer of nerve impulse from one neuron to the other.
5-HT is found in the enteric nervous system located in the gastrointestinal tract and it helps in modulating cognition, memory, sleep, and numerous physiological processes.
Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine and citalopram are used to increase the level of 5-HT in the synaptic cleft by inhibiting its reuptake into the presynaptic terminal.
1. Explain why food lasts longer when placed in the refrigerator as opposed to on the counter in the kitchen.
2. List and describe four factors that affect the rate of a reaction.
3. Sketch a potential energy diagram for the following reaction: N2(g)+3H2(g)-->2NH3(g)
Use Table I in the Chemistry Reference Table to identify the following on your graph: potential energy of reactants, potential energy of products, activation energy, and heat of reaction. State the value of the enthalpy and whether the reaction is endothermic or exothermic. Label the y-axis and potential energy and x-axis as reaction coordinate.
4. Describe and explain the effect of (a) the increase in temperature, (b) the increase in concentration of C2H4, and (c) a decrease in pressure to the following system at equilibrium: 2C + 2H2 + heat ⇌ C2H4
It last longer because it slows down the spread of bacteria.
Temperature, concentration, particle size, use of a catalyst.
When the following oxidation-reduction reaction in acidic solution is balanced, what is the
lowest whole-number coefficient for Rb+ (aq)?
Rb(s) + Sr2+ (aq) → Rb+(aq) + Sr(s)
Answer:
2Rb(s) + Sr^+(aq) → 2Rb^+ (aq) + Sr(s)
Explanation:
In a redox reaction, we must ensure that the number of electrons gained equals the number of electrons lost in the reduction and oxidation half reaction equations respectively.
Having that in mind;
Oxidation half reaction;
2Rb(s) ---->2Rb^+(aq) + 2e
Reduction half equation;
Sr^2+(aq) + 2e---> Sr(s)
Hence, the overall redox reaction equation is;
2Rb(s) + Sr^+(aq) → 2Rb^+ (aq) + Sr(s)
Desclony When Fe(NO3)2 dissolves in water, what particles are present in the solution?
Answer:
hjfhgjgjgjghgjgjhgjhhjh
Identify the conjugate acid/base pairs in each of the following equations:
(a) H2S + NH3 ⇔ NH4+ + HS-
Pair 1: H2S and
Pair 2: NH3 and
(b) HSO4- + NH3 ⇔ SO42- + NH4+
Pair 1: HSO4- and
Pair 2: NH3 and
(c) HBr + CH3O- ⇔ Br- + CH3OH
Pair 1: HBr and
Pair 2: CH3O- and
(d) HNO3 + H2O → NO3- + H3O+
Pair 1: HNO3 and
Pair 2: H2O and
Answer:
(a) Pair 1: H₂S and HS⁻
Pair 2: NH₃ and NH₄⁺
(b) Pair 1: HSO₄⁻ and SO₄⁻
Pair 2: NH₃ and NH₄⁺
(c) Pair 1: HBr and Br⁻
Pair 2: CH₃O⁻ and CH₃OH
(d) Pair 1: HNO₃ and NO₃⁻
Pair 2: H₃O⁺
Explanation:
When an acid loses its proton (H⁺), a conjugate base is produced.
When a base accepts a proton (H⁺), it forms a conjugate acid.
(a) H₂S is an acid. When it loses a proton, it forms the conjugate base HS⁻.
NH₃ is a base. When NH₃ gains a proton, it forms the conjugate acid NH₄⁺
(b) The acid HSO₄⁻ loses a H⁺ ion and forms the conjugate base SO₄²⁻.
The base NH₃ accepts a H⁺ ion to form the conjugate acid NH₄⁺.
(c) HBr is an acid. When loses the H⁺ ion, it forms the conjugate base Br⁻.
CH₃O⁻ accepts a H⁺ ion to form the conjugate acid CH₃OH.
(d) HNO₃ loses a proton to form the conjugate base NO₃⁻.
H₂O gains a proton to form the conjugate acid H₃O⁺.
How many milliliters of a 6.00 M NaCl solution are needed to make 250.0 milliliters of a 0.500 M NaCl solution?
Answer:
20,8ml NaCl 6M
Explanation:
C1V1 = C2V2
Help me please , I got 0.003 for a I need help with b and c
Answer:
(a) The moles of CuSO₄ is 3.125 × 10⁻³ moles.
(b) The moles of Cu is 3.125 × 10⁻³ moles.
(c) The mass of Cu is 0.2 g.
Explanation:
Given:
Mass of CuSO₄ = 0.5 g
Molar mass of CuSO₄ = 160 g/mol
The given balanced chemical equation is:
[tex]2Al+3CuSO_4\rightarrow 3Cu+Al_2(SO_4)_3[/tex]
Part (a):
Calculating the moles of CuSO₄.
[tex]\text{Moles of } CuSO_4=\frac{\text{Mass of }CuSO_4}{\text{Molar mass of }CuSO_4}\\\\\text{Moles of } CuSO_4=\frac{0.5g}{160g/mol}\\\\\text{Moles of } CuSO_4=3.125\times 10^{-3}mol[/tex]
Thus, the moles of CuSO₄ is 3.125 × 10⁻³ moles.
Part (b):
Calculating the moles of Cu.
From the balanced chemical equation, we conclude that:
As, 3 moles of CuSO₄ reacts to give 3 moles of Cu
So, 3.125 × 10⁻³ moles of CuSO₄ reacts to give 3.125 × 10⁻³ moles of Cu
Thus, the moles of Cu is 3.125 × 10⁻³ moles.
Part (c):
Calculating the mass of Cu.
Mass of Cu = Moles of Cu × Molar mass of Cu
Molar mass of Cu = 64 g/mol
Mass of Cu = (3.125 × 10⁻³ mole) × (64 g/mol)
Mass of Cu = 0.2 g
Thus, the mass of Cu is 0.2 g.
The general formula for ____________ and ____________ are CnH2n+2 and CnH2n , respectively. Axial and equatorial hydrogen atoms are interconverted during a ____________ . The anti conformation is ____________ in energy than a gauche conformation. The increase in energy when tetrahedral bond angles deviate from the optimum angle of 109.5° is known as ____________ strain. The ____________ position has more room than the ____________ position, so larger substituents are more stable in the equatorial position.
Answer:
Alkanes
Cycloalkanes
Ring flip
Lower
Angle
Equatorial
Axial
Explanation:
For alkanes, the general molecular formula is CnH2n+2 while for cycloalkanes, the general molecular formula is CnH2n.
The cycloalkanes could undergo a ring flip in which axial and equatorial hydrogen atoms are interconverted.
The lower energy conformation of alkanes is the anti conformation and not the gauche conformation due to steric strain.
When the bond angle in alkanes deviate from the ideal 109.5°, an angle strain has occurred.
For bulky groups, the equatorial position his preferred since it has more room than the axial position.
Identify the bronsted-lowry acid and the bronsted-lowry base in this reaction on the left side of each of the following equations, and also identify the conjugate acid and conjugate base of each on the right side.
mathrm { NH } _ { 4 } ^ { + } ( a q ) + mathrm { CN } ^ { - } ( a q ) rightleftharpoons mathrm { HCN } ( a q ) + mathrm { NH } _ { 3 } ( a q )
Answer: [tex]NH_4^+[/tex] is an acid, [tex]CN^-[/tex] is a base, [tex]NH_3[/tex] is conjugate base and [tex]HCN[/tex] is conjugate acid
Explanation:
According to Bronsted and Lowry's theory:
An acid is defined as a proton donor while a base is defined as a proton acceptor.
In a chemical reaction, an acid loses a proton to form a conjugate base while a base accepts a proton to form conjugate acid.
For the given chemical reaction:
[tex]NH_4^+(aq)+CN^-(aq)\rightleftharpoons HCN(aq)+NH_3(aq)[/tex]
[tex]NH_4^+[/tex] is losing a proton thus it is an acid to form [tex]NH_3[/tex] which is its conjugate base
[tex]CN^-[/tex] is gaining a proton thus it is a base to form [tex]HCN[/tex] which is its conjugate acid
Hence, [tex]NH_4^+[/tex] is an acid, [tex]CN^-[/tex] is a base, [tex]NH_3[/tex] is conjugate base and [tex]HCN[/tex] is conjugate acid
Which of the following is true about oxidation-reduction reactions?
=============================================================
One atom is oxidized and one is reduced
Both atoms are oxidized and reduced
The total number of electrons changes
One atom can be oxidized without one being reduced
Answer:
the last one probably
Explanation:
name hydrogen ion
what the symbolotom
Answer:
H+
Explanation:
it's H+
as you see hydrogen ion it could H+
A penny has a thickness of approximately 1.0 mm. If you stacked Avogadro's number of pennies one on top of the other on Earth's surface, how far would the stack extend (in kilometers). For comparison, the sun is about 150 million km from Earth and the nearest star (Proxima Centauri) is about 40 trillion km from Earth].
Answer:
6.02 × 10²⁷ km
Explanation:
Step 1: Calculate the height of the stack of pennies
A penny has a thickness of approximately 1.0 mm. If you stacked Avogadro's number of pennies (6.02 × 10²³ pennies) one on top of the other on Earth's surface, the height of the stack of pennies would be:
6.02 × 10²³ pennie × 1.0 mm/1 pennie = 6.02 × 10²³ mm
Step 2: Convert 6.02 × 10²³ mm to kilometers
We will use the following conversion factors.
1 km = 10³ m1 m = 10³ mm6.02 × 10²³ mm × 1 m/10³ mm × 1 km/10³ m = 6.02 × 10²⁷ km
2 . a) b) (1) List three oxides of nitrogen ( 3ks) State Charles law (2mks) (111) A given mass of gas occupies 300cm at 900mmHg if temperature remains constant (5mks) State one industrial application in each of the following Crystallization (2mks) (11) Filtration (2mks) (111) Fractional distillation (2mks) (1) State the property of hydrogen which makes it suitable for filling meteorological balloons (2mks) Why is helium preferred to hydrogen in filling balloons? (2mks) (1) с) 3. a) b) (1) List the steps involved in the purification of water for town supply State two differences between rusting and burning (1) Copy and complete the following table Element No of neutron Electron Group configuration 1 1522522p5 ZOR (ii) State the family to which the elements belong State the two differences between fine chemical and heavy chemicals 32P 130 19 c) 1. a ( List the three types of particles present in an atom Name the element that does not contain all the three particles What is the particle that is not present What is isomerism? b)
ask correctly so that your points cant make fun of others
Exercise 2: (7 points)
Augmentin
Augmentin is a drug formed by amoxicillin of molecular formula C16H19N3O5S.3H20 and molar mass 419 g.mol"! Augmenting is used to treat infections caused by certain bacteria. The normal dose is 500mg of tablet each 12 hours. The maximum dose is 40g of Augmentin for 10 days. Augmentin generally has a normal action; a high dose (overdose) in Augmentin causes kidney problems.
1) Explain in which case we use Augmentin. 2) 2.1) Il a patients dissolved in the water an Augmentin tablet of 500mg to prepare a 100ml solution, determine the mass concentration and molar concentration of the obtained solution 2.2) Write the procedures followed to prepare this solution and indicate the materials used in this preparation.
3) If a patient takes daily 100ml of Augmentin solution of concentration 50g L for 10 days, will he suffer from kidney problems?
Answer:
See explanation
Explanation:
I) from the question;
500 × 10^-3 g dissolves in 100ml
xg dissolves in 1000ml
x = 500 × 10^-3 g × 1000ml/100 ml
x= 5 g/L
Mass concentration = molar concentration × molar mass
Molar concentration = Mass concentration/ molar mass
Molar concentration = 5g/L/419 g/mol
Molar concentration = 0.0119 M
ii) To prepare this solution, measure out 500mg with a weighing balance. Transfer the solid to a standard 100 ml volumetric flask. Make up to the 100ml mark with distilled water.
iii) mass concentration of the solution = 50 g/L
Volume of the solution= 100 ml
Mass of the solid = 50 g/L × 100/1000 L
Mass of solid = 5g
This 5g was taken for 10 days, hence a total of 50 g
Since the normal dose of the drug is 40g for ten days, the patient will suffer from kidney problems because he/she has taken the drug above the recommended dosage.
What are the characteristics of an acid-base neutralization reaction?
