A phospholipid has a charged head and an uncharged tail.
Would an electron in the 1s orbital of lithium require the same energy to move to a higher energy level as an electron in the
1s orbital of silver?
Answer:
See explanation
Explanation:
We must remember that the energy required to move an electron from the 1s orbital to a higher energy level depends on the size of the nuclear charge.
The higher the nuclear charge, the more closely held the 1s electron of the atom is to the nucleus and the more difficult it is to excite this electron.
Hence, it requires more energy to excite the 1s electron of silver having a larger size of nuclear charge than it is to excite a 1s electron in lithium.
What is the chemical equation for F2 + At- -->
Answer:
F₂ + 2At --> 2AtF
Explanation:
Astatine is a halogen but is not diatomic. It's possible oxidation states are 1⁺, 1⁻, or 5⁺. Fluorine only has the possible oxidation states of 1⁺ or 1⁻.
To form any chemical bond, the following happens:
O A. Two atoms exchange protons between each other
B. Two atoms are mixed together
C. Two atoms share or transfer electrons
O
D. Two compounds are attracted
Answer:
B. two atoms share or transfer electrons
Explanation:
for a chemical bond to occur there must be association of atoms into molecules,ions , crystals or other species that make up familiar substances
A certain liquid has a normal boiling point of and a boiling point elevation constant . A solution is prepared by dissolving some glycine () in of . This solution boils at . Calculate the mass of that was dissolved. Round your answer to significant digit.
The question is incomplete, the complete question is:
A certain substance X has a normal freezing point of [tex]-6.4^oC[/tex] and a molal freezing point depression constant [tex]K_f=3.96^oC.kg/mol[/tex]. A solution is prepared by dissolving some glycine in 950. g of X. This solution freezes at [tex]-13.6^oC[/tex] . Calculate the mass of urea that was dissolved. Round your answer to 2 significant digits.
Answer: The mass of glycine that can be dissolved is [tex]1.3\times 10^2g[/tex]
Explanation:
Depression in the freezing point is defined as the difference between the freezing point of the pure solvent and the freezing point of the solution.
The expression for the calculation of depression in freezing point is:
[tex]\text{Freezing point of pure solvent}-\text{freezing point of solution}=i\times K_f\times m[/tex]
OR
[tex]\text{Freezing point of pure solvent}=\text{Freezing point of solution}=i\times K_f\times \frac{m_{solute}\times 1000}{M_{solute}\times w_{solvent}\text{(in g)}}[/tex] ......(1)
where,
Freezing point of pure solvent = [tex]-6.4^oC[/tex]
Freezing point of solution = [tex]-13.6^oC[/tex]
i = Vant Hoff factor = 1 (for non-electrolytes)
[tex]K_f[/tex] = freezing point depression constant = [tex]3.96^oC/m[/tex]
[tex]m_{solute}[/tex] = Given mass of solute (glycine) = ?
[tex]M_{solute}[/tex] = Molar mass of solute (glycine) = 75.07 g/mol
[tex]w_{solvent}[/tex] = Mass of solvent = 950. g
Putting values in equation 1, we get:
[tex]-6.4-(-13.6)=1\times 3.96\times \frac{m_{solute}\times 1000}{75.07\times 950}\\\\m_{solute}=\frac{7.2\times 75.07\times 950}{1\times 3.96\times 1000}\\\\m_{solute}=129.66g=1.3\times 10^2g[/tex]
Hence, the mass of glycine that can be dissolved is [tex]1.3\times 10^2g[/tex]
The physical properties of a substance containing the bonded atoms y and z ?
Someone pls help me ::/:/
How much energy must be added to 250.0 g of ice at 0.00 °C to raise the
temperature of the water to 50.0 °C? The heat of fusion for water is 334
J/g. The specific heat of water is 4.184 J/g.K.
Answer:
136 KJ
Explanation:
We'll begin by calculating the heat required to melt the ice. This can be obtained as follow:
Mass (M) = 250 g
Heat of fusion (Hբ) = 334 J/gºC
Heat (Q₁) required to melt the ice =?
Q₁ = MHբ
Q₁ = 250 × 334
Q₁ = 83500 J
Next, we shall determine the heat required to change the temperature. This can be obtained as follow:
Mass (M) = 250 g
Initial temperature (T₁) = 0 °C
Final temperature (T₂) = 50 °C
Specific heat capacity (C) = 4.184 J/gºC
Heat (Q₂) required to change the temperature =?
Q₂ = MC(T₂ – T₁)
Q₂ = 250 × 4.184 (50 – 0)
Q₂ = 1046 × 50
Q₂ = 52300 J
Next, we shall determine the total heat required.
Heat (Q₁) required to melt the ice = 83500 J
Heat (Q₂) required to change the temperature = 52300 J
Total heat (Qₜ) required =?
Qₜ = Q₁ + Q₂
Qₜ = 83500 + 52300
Qₜ = 135800 J
Finally, we shall convert 135800 J to KJ. This can be obtained as follow:
1000 J = 1 KJ
Therefore,
135800 J = 135800 J × 1 KJ / 1000 J
135800 J ≈ 136 KJ
Thus, the total heat required is 136 KJ.
Which of the following hydrocarbons will be the most acidic?
Pentane
Propylene
Isobutane
Ethene
Acetylene
Answer:
its answer is (Acetylene)
The acid-dissociation constants for three acids are shown in the table.
Which is the strongest acid?
The strongest acid as per dissociation constant is hydrochloric acid.
What are acids?Acids are defined as substances which on dissociation yield H+ ions , and these substances are sour in taste. Compounds such as HCl, H₂SO₄ and HNO₃ are acids as they yield H+ ions on dissociation.
According to the number of H+ ions which are generated on dissociation acids are classified as mono-protic , di-protic ,tri-protic and polyprotic acids depending on the number of protons which are liberated on dissociation.
Acids are widely used in industries for production of fertilizers, detergents batteries and dyes.They are used in chemical industries for production of chemical compounds like salts which are produced by neutralization reactions.Acids are also used in titrations.
Learn more about acids,here:
https://brainly.com/question/29796621
#SPJ2
Indica, con base en la siguiente ecuación:
HNO3 + H2S
NO + S + H30
a) Los números de oxidación de todos los átomos que forman cada compuesto
o elemento.
b) los átomos cuyo número de oxidación varía.
c) El elemento que se reduce y el que se oxida.
d) El agente oxidante y el agente reductor.
e) El átomo que gana electrones y el átomo que los pierde.
f) Los coeficientes apropiados para balancear la ecuación química.
Which best defines the term drug
Answer:
a medicine or other substance which has a physiological effect when ingested or otherwise introduced into the body.
Explanation:
3 valance electrons on the 4th shell
A sample of a gas has a volume of 1.5L at 150K. If the gas is heated to 235K at constant pressure, what will its final volume be
Answer:
2.35 L
Explanation:
From Charles Law
Applying,
V/T = V'/T'................. Equation 1
Where V = Initial volume of the gas, V' = Final volume of the gas, T = Initial Temperature of the gas, T' = Final temperature of the gas.
Make V' the subject of the equation
V' = VT'/T............... Equation 2
From the question,
Given: V = 1.5 L, T = 150 K, T' = 235 K,
Substitute these values into equation 2
V' = (1.5×235)/150
V' = 2.35 L
Hence the final volume of the gas is 2.35 L
the first liquid that comes out of a woman's breast after delivery is called?
The first liquid (milk) that comes out of a woman's breast after delivery is called [tex]\sf\purple{colostrum}[/tex].
[tex]\large\mathfrak{{\pmb{\underline{\orange{Happy\:learning }}{\orange{!}}}}}[/tex]
Identify the calculations possible using only 28.02 g/mol as a conversion factor. Select one or more:
The question is incomplete, the complete question is:
Identify the calculations possible using only 28.02 g/mol as a conversion factor. Select one or more:
(a): Calculate the grams of [tex]N_2[/tex] in 10.58 L of nitrogen gas
(b): Calculate the grams of [tex]N_2[/tex] in [tex]5.03\times 10^{20}[/tex] moles of nitrogen gas
(c): Calculate the moles of [tex]N_2[/tex] molecules in 3.94 grams of nitrogen gas
(d): Calculate the moles of [tex]N_2[/tex] molecules in 4.73 L of nitrogen gas
Answer: The correct options are (b) and (c).
Explanation:
We are given:
Molar mass of [tex]N_2[/tex] = 28.02 g/mol
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
At STP conditions:
1 mole of gas occupies 22.4 L of volume
For the given options:
(a): Volume is given and to calculate the mass of [tex]N_2[/tex], we need to use both the conversion factors above.
The equation formed will be:
Mass of [tex]N_2[/tex] = [tex]\frac{1mol}{22.4L}\times 10.58L\times 28.02 g/mol[/tex]
(b): Moles are given and to calculate the mass of [tex]N_2[/tex], we need only the first conversion factor.
The equation formed will be:
Mass of [tex]N_2[/tex] = [tex](5.03\times 10^{20}mol)\times 28.02g/mol[/tex]
(c): Mass is given and to calculate the moles of [tex]N_2[/tex] molecules, we need only the first conversion factor.
The equation formed will be:
Moles of [tex]N_2[/tex] molecules = [tex]\frac{3.94 g}{28.02g/mol}[/tex]
(d): Volume is given and to calculate the moles of [tex]N_2[/tex] molecules, we need only the second conversion factor.
The equation formed will be:
Moles of [tex]N_2[/tex] molecules = [tex]\frac{1mol}{22.4L}\times 4.73L[/tex]
Hence, the correct option is (b) and (c)
Using only 28.02 g/mol as a conversion factor, we can:
(b): Calculate the grams of N₂ in 5.03 × 10²⁰ moles of nitrogen gas. (c): Calculate the moles of N₂ molecules in 3.94 grams of nitrogen gas.We want to identify the conversion factors required in a series of calculations.
What is a conversion factor?A conversion factor is an arithmetical multiplier for converting a quantity expressed in one set of units into an equivalent expressed in another.
28.02 g/mol, which is the molar mass of nitrogen, is a conversion factor to convert moles to mass and vice versa.
(a): Calculate the grams of N₂ in 10.58 L of nitrogen gas.We want to convert 10.58 L (volume) to grams (mass). We need to conversion factors:
22.4 L/mol is the conversion factor to convert volume to moles.28.02 g/mol is the conversion factor to convert moles to mass.(b): Calculate the grams of N₂ in 5.03 × 10²⁰ moles of nitrogen gas.We want to convert 5.03 × 10²⁰ moles (moles) to grams (mass). We can do so by just using 28.02 g/mol as the conversion factor.
(c): Calculate the moles of N₂ molecules in 3.94 grams of nitrogen gas.We want to convert 3.94 grams (mass) to moles. We can do so by just using 28.02 g/mol as the conversion factor.
(d): Calculate the moles of N₂ molecules in 4.73 L of nitrogen gas.We want to convert 4.73 L (volume) to moles. The required conversion factor is 22.4 L/mol.
Using only 28.02 g/mol as a conversion factor, we can:
(b): Calculate the grams of N₂ in 5.03 × 10²⁰ moles of nitrogen gas. (c): Calculate the moles of N₂ molecules in 3.94 grams of nitrogen gas.The question is incomplete, the complete question is:
Identify the calculations possible using only 28.02 g/mol as a conversion factor. Select one or more:
(a): Calculate the grams of N₂ in 10.58 L of nitrogen gas.
(b): Calculate the grams of N₂ in 5.03 × 10²⁰ moles of nitrogen gas.
(c): Calculate the moles of N₂ molecules in 3.94 grams of nitrogen gas.
(d): Calculate the moles of N₂ molecules in 4.73 L of nitrogen gas.
Learn more about conversion factors here: https://brainly.com/question/97386
Which of the following is considered a nucleon?
proton
neutron
All of the above
None of the above
How many products might be formed on chlorination of o-xylene (o-dimethylbenzene), m-xylene, and p-xylene
What does a dissolved salt look like?
The diagram shows a food chain.
Which term best describes the green plant in the food chain?
antiter
A. Competitor
B. Producer
C. Consumer
D. Predator
An imaginary line dividing the earth's surface into two hemisphere the northern and southern hemisphere, it is locatedat 0⁰, which of the following imaginary lines is being described? a.equator b.latitude c.longitude d.prime meridian
Answer:
A. Equator
Explanation:
The equator is located in the centre of the Earth, dividing the northern and southern hemispheres.
Answer:
Equator because equator divides the earth into Northern and Southern hemisphere.
Rank these transition metal ions in order of decreasing number of unpaired electrons.
a. Fe^3
b. Mn^4+
c. V3+
d. Ni^2+
e. Cu^+
Answer: The given transition metal ions in order of decreasing number of unpaired electrons are as follows.
[tex]Mn^{4+} > V^{3+} = Ni^{2+} > Fe^{3+} > Cu^{+}[/tex]
Explanation:
In atomic orbitals, the distribution of electrons of an atom is called electronic configuration.
The electronic configuration in terms of noble gases for the given elements are as follows.
Atomic number of Fe is 26.[tex]Fe^{3+} - [Ar] 3d^{5}[/tex]
So, there is only 1 unpaired electron present in [tex]Fe^{3+}[/tex].
Atomic number of Mn is 25.[tex]Mn^{4+} - [Ar]3d^{3}[/tex]
So, there are only 3 unpaired electrons present in [tex]Mn^{4+}[/tex].
Atomic number of V is 23.[tex]V^{3+} - [Ar] 3d^{2}[/tex]
So, there are only 2 unpaired electrons present in [tex]V^{3+}[/tex].
Atomic number of Ni is 28.[tex]Ni^{2+} - [Ar] 3d^{8}[/tex]
So, there will be 2 unpaired electrons present in [tex]Ni^{2+}[/tex].
Atomic number of Cu is 29.[tex]Cu^{+} - [Ar] 3d^{10}[/tex]
So, there is no unpaired electron present in [tex]Cu^{+}[/tex].
Therefore, given transition metal ions in order of decreasing number of unpaired electrons are as follows.
[tex]Mn^{4+} > V^{3+} = Ni^{2+} > Fe^{3+} > Cu^{+}[/tex]
Thus, we can conclude that given transition metal ions in order of decreasing number of unpaired electrons are as follows.
[tex]Mn^{4+} > V^{3+} = Ni^{2+} > Fe^{3+} > Cu^{+}[/tex]
A 100.00 mL volumetric flask weighs 35.9325 g. When an unknown solid is added to it, the flask and sample weigh 48.8565 g. Deionized water is added to the calibration mark. The flask, sample, and water together weigh 140.8321 g. Calculate the density of the unknown, assuming the density of water is 0.998203 g/mL.
Answer:
1.64 g/mL
Explanation:
Step 1: Calculate the mass of the solid
m(solid+flask) = m(solid) + m(flask)
m(solid) = m(solid+flask) - m(flask)
m(solid) = 48.8565 g - 35.9325 g = 12.9240 g
Step 2: Calculate the mass of water
m(solid+flask+water) = m(solid+flask) + m(water)
m(water) = m(solid+flask+water) - m(solid+flask)
m(water) = 140.8321 g - 48.8565 g = 91.9756 g
Step 3: Calculate the volume occupied by 91.9756 g of water
The density of water is 0.998203 g/mL.
91.9756 g × 1 mL/0.998203 g = 92.1412 mL
Step 4: Calculate the volume occupied by the solid
The 100.00 mL are occupied by the solid and the water.
100.00 mL = V(solid) + V(water
V(solid) = 100.00 mL - V(water)
V(solid) = 100.00 mL - 92.1412 mL = 7.86 mL
Step 5: Calculate the density of the solid
12.9240 g of the solid occupy 7.86 mL.
ρ = 12.9240 g/7.86 mL = 1.64 g/mL
m
Un cocodrilo se arrastró 25 m hacia la derecha con una velocidad promedio de –1.2 -.
¿Cuántos segundos se arrastró el cocodrilo?
Answer:
El cocodrilo se arrastró durante 20.833 segundos.
Explanation:
El enunciado presenta omisiones y errores conceptuales. La forma correcta es la siguiente: "Un cocodrilo se arrastró 25 metros hacia la derecha con una rapidez promedio de 1.2 metros por segundo. ¿Cuántos segundos se arrastró el cocodrilo?"
Consideremos que el cocodrilo tiene un movimiento rectilíneo uniforme, el tiempo requerido para el recorrido se calcula con la siguiente ecuación cinemática:
[tex]t = \frac{x}{v}[/tex] (1)
Donde:
[tex]x[/tex] - Distancia recorrida, en metros.
[tex]v[/tex] - Rapidez del cocodrilo, en metros por segundo.
[tex]t[/tex] - Tiempo, en segundos.
Si [tex]x = 25\,m[/tex] y [tex]v = 1.2\,\frac{m}{s}[/tex], entonces el tiempo empleado por el cocodrilo es:
[tex]t = \frac{25\,m}{1.2\,\frac{m}{s} }[/tex]
[tex]t = 20.833\,s[/tex]
El cocodrilo se arrastró durante 20.833 segundos.
Unit 09: Acids, Bases, and the PH Scale
Answer:
Err... Mate are we suppose to give you resources on this topic, or do we just err respond? if I will give you resources?
Explanation:
61. Using the symbol of the previous noble gas to indicate the core
electrons, write the electron configuration for each of the fol-
lowing elements.
a. scandium, Z= 21 c. lanthanum, Z= 57
b. yttrium, Z = 39
d. actinium, Z= 89
Answer:
Scandium, with atomic number of 21 = [Ar]3d¹4s²
Yttrium, with atomic number of 39 = [Kr]4d¹5s²
Lanthanum, with atomic number of 57 = [Xe]5d¹6s²
Actinium, with atomic number of 89 = [Rn]6d¹7s²
Explanation:
The electronic configuration of atoms of elements describes how electrons are arranged in the atomic orbitals of the atom. The electron configurations of atoms in standard notation is usually written sequentially with all electron-containing atomic subshells (s, p, d and f) and the number of electrons they contain in superscript. For example, the electron configuration of Neon is 1s²2s²2p⁶. However, an abbreviated notation can be used especially for elements having large atomic numbers. The symbol of the previous noble gas in square brackets indicating the core electrons is written before the outermost shell electrons of the atom. For example, the abbreviated electron configuration of sodium is [Ne]3s¹.
The electronic configuration of the given elements are shown below:
Scandium, with atomic number of 21 = [Ar]3d¹4s²
Yttrium, with atomic number of 39 = [Kr]4d¹5s²
Lanthanum, with atomic number of 57 = [Xe]5d¹6s²
Actinium, with atomic number of 89 = [Rn]6d¹7s²
A solution has a pH of 2.5. what is the H+
Answer: The concentration of [tex]H^+[/tex] in the solution is [tex]3.16\times 10^{-3}M[/tex]
Explanation:
pH is defined as the negative logarithm of hydrogen ion concentration present in the solution.
[tex]pH=-\log [H^+][/tex] .....(1)
We are given:
pH of solution = 2.5
Putting values in equation 1, we get:
[tex]2.5=-\log [H^+][/tex]
[tex][H^+]=10^{-2.5}[/tex]
[tex][H^+]=3.16\times 10^{-3}M[/tex]
Hence, the concentration of [tex]H^+[/tex] in the solution is [tex]3.16\times 10^{-3}M[/tex]
Acetylene gas, C2H2, is produced as a result of the following reaction: CaC2 + 2H2O ----> C2H2 + Ca(OH)2.
(a) If 32 grams of CaC2 are consumed in this reaction, how many moles of water are needed ?
(b) How Many moles of each product would form ?
Given the data from the question,
A. The number of mole of water needed for the reaction is 1 mole
Bi. The number of mole of C₂H₂ formed is 0.5 mole
Bii. The number of mole of Ca(OH)₂ formed is 0.5 mole
How to determine the mole of CaC₂Mass of CaC₂ = 32 gMolar mass of CaC₂ = 40 + (12×2) = 64 g/mol Mole of CaC₂ =?Mole = mass / molar mass
Mole of CaC₂ = 32 / 64
Mole of CaC₂ = 0.5 mole
A. How to determine the mole of water needeBalanced equation
CaC₂ + 2H₂O —> C₂H₂ + Ca(OH)₂
From the balanced equation above,
1 mole of CaC₂ required 2 moles of H₂O
Therefore,
0.5 mole of CaC₂ will require = 0.5 × 2 = 1 mole of H₂O
Thus, 1 mole of H₂O is needed for the reaction.
Bi. How to determine the mole of C₂H₂ produced
Balanced equation
CaC₂ + 2H₂O —> C₂H₂ + Ca(OH)₂
From the balanced equation above,
1 mole of CaC₂ reacted to produce 1 mole of C₂H₂
Therefore,
0.5 mole of CaC₂ will also react to produce 0.5 mole of C₂H₂
Thus, 0.5 mole of C₂H₂ was obtained from the reaction
Bii. How to determine the mole of Ca(OH)₂ producedBalanced equation
CaC₂ + 2H₂O —> C₂H₂ + Ca(OH)₂
From the balanced equation above,
1 mole of CaC₂ reacted to produce 1 mole of Ca(OH)₂
Therefore,
0.5 mole of CaC₂ will also react to produce 0.5 mole of Ca(OH)₂
Thus, 0.5 mole of Ca(OH)₂ was obtained from the reaction
Learn more about stoichiometry:
https://brainly.com/question/14735801
Which element has a higher first ionization energy than chlorine (Cl)?
A. Argon (Ar)
B. Phosphorus (P)
C. Lithium (Li)
D. Iodine (I)
Answer:
Argon
Explanation:
It has more electron than chlorine
Which of the following reactions would result in decreased entropy?
O A. H20(g) → H20(1)
O B. CO2(s) → CO2(9)
O C. 203(9) ► 302(9)
O D. N2204(9) ► 2NO39)
Answer:
A
Explanation:
A P E X
Glycerol. C3HgO3, is a substance used extensively in the manufacture of cosmetics, foodstuffs, antifreeze, and plastics. Glycerol is a water-soluble liquid
with a density of 1.2656 g/mL at 15 °C. Calculate the molarity of a solution of glycerol made by dissolving 50.000 mL glycerol at 15 °C in enough water to
make 250.00 mL of solution. The molecular weight of C3HgO3 is 92.094 amu.
O A 0.6871
O B. 3.600
O C. 63.28
O 0.92.10
O E. 2.749
Answer: The correct option is E.) 2.749 M.
Explanation:
Density is defined as the ratio of mass and volume of a substance.
[tex]\text{Density}=\frac{\text{Mass}}{\text{Volume}} [/tex] ......(1)
Given values:
Volume of glycerol = 50.0 mL
Density of glycerol = 1.2656 g/mL
Putting values in equation 1, we get:
[tex]\text{Mass of glycerol }=(1.2656g/mL\times 50.0mL)=63.28g[/tex]
Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:
[tex]\text{Molarity of solution}=\frac{\text{Given mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (mL)}}[/tex] .....(2)
Given values:
Given mass of glycerol = 63.28 g
Molar mass of glycerol = 92.094 g/mol
Volume of the solution = 250.00 mL
Putting values in equation 2, we get:
[tex]\text{Molarity of solution}=\frac{63.28\times 1000}{92.094\times 250.00}\\\\\text{Molarity of solution}=2.749M[/tex]
Hence, the correct option is E.) 2.749 M.
12. The reaction 2NO, (g) = N20,(g) reaches equilibrium.
How does increasing the pressure on this system affect the amount o
The amount of N20 remains the same.
The amount of N20 increases.
The amount of N20 decreases.
Answer:
The amount of N2O4 increases.
Explanation:
Based on LeCh's principle, a change in the state of an equilibrium produce an effect in the system that try to restore the initial equilibrium.
For example, in the problem, the change is the increasing in the pressure. The system will try to decrease the pressure of the system. To decrease the pressure the system needs to decrease the moles of gas. As 2 moles of NO2 produce 1 mole of N2O4, the system will:
Shift to the right increasing the amount of N2O4 and decreasing the amount of NO2. Right option is:
The amount of N2O4 increases.