Answer:
joe biden
Explanation:
It was DONALD TRUMP :) But Joe Biden got elected :(
What is the name of the groups that contain Iron(Fe) and Gold(Au)?
Answer:
Transition Metals
Explanation:
Answer:
Group 8 & 11
Explanation:
Transition Metals
how do you determine number of valence electrons an element has
Answer:the first column has one valance electron the second has 2 and so on.
The only exception is helium that has 2.
Explanation:
Which of the following statement best defines matter?
Answer:matter is anything has mass and take up space
Explanation:
15.0 moles of gas are in a 8.00 L tank at 22.3 ∘C∘C . Calculate the difference in pressure between methane and an ideal gas under these conditions. The van der Waals constants for methane are a=2.300L2⋅atm/mol2 a=2.300L2⋅atm/mol2 and b=0.0430L/molb=0.0430L/mol.
Answer:
[tex]\Delta P=4.10atm[/tex]
Explanation:
Hello!
In this case, since the ideal gas equation is used under the assumption of no interaction between molecules and perfectly sphere-shaped molecules but the van der Waals equation actually includes those effects, we can compute each pressure as shown below, considering the temperature in kelvins (22.3+273.15=295.45K):
[tex]P^{ideal}=\frac{nRT}{V}=\frac{15.0mol*0.08206\frac{atm*L}{mol*K}*295.45K}{8.00L}=45.5atm[/tex]
Next, since the VdW equation requires the molar volume, we proceed as shown below:
[tex]v=\frac{8.00L}{15.0mol}=0.533\frac{L}{mol}[/tex]
Now, we use its definition:
[tex]P^{VdW}=\frac{RT}{v-b} -\frac{a}{v^2}[/tex]
Thus, by plugging in we obtain:
[tex]P^{VdW}=\frac{0.08206\frac{atm*L}{mol*K}*295.45K}{0.533mol/L-0.0430L/mol} -\frac{2.300L^2*atm/mol^2}{(0.533L/mol)^2}\\\\P^{VdW}=49.44atm-8.09atm\\\\P^{VdW}=41.4atm[/tex]
Thus, the pressure difference is:
[tex]\Delta P=45.5atm-41.4atm\\\\\Delta P=4.10atm[/tex]
Best regards!
While performing a neutralization reaction, Jonna added 22.63 mL of 0.142 M H2SO4 to 46.21 mL of 0.304 M KOH. How many moles of OH- are unreacted in the solution after the neutralization is complete?
Answer:
7.623 x 10⁻³ mol OH⁻
Explanation:
The reaction that takes place is:
H₂SO₄ + 2KOH → K₂SO₄ + 2H₂ONow we calculate how many moles of each reagent were added:
H₂SO₄ ⇒ 22.63 mL * 0.142 M = 3.213 mmol H₂SO₄KOH ⇒ 46.21 mL * 0.304 M = 14.05 mmol KOHWe calculate how many OH⁻ moles reacted with H₂SO₄:
3.213 mmol H₂SO₄ * [tex]\frac{2mmolOH^-}{1mmolH_2SO_4}[/tex] = 6.427 mmol OH⁻Finally we substract the OH⁻ moles that reacted from the added ammount of OH⁻ moles:
14.05 mmol KOH - 6.427 mmol OH⁻ = 7.623 mmol OH⁻7.623 mmol / 1000 = 7.623 x 10⁻³ mol OH⁻The number of moles of OH⁻ that are unreacted in the solution after the neutralization reaction is complete is 0.00770 moles OR 7.70×10⁻³ moles
First, we will write a balanced chemical equation for the neutralization reaction
The balanced chemical equation for the neutralization reaction is
H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O
This means
1 mole of H₂SO₄ reacts with 2 moles of KOH to give 1 mole of K₂SO₄ and 2 moles of H₂O
To determine the number of moles of OH⁻ that are unreacted after the neutralization is complete,
We will determine the number of moles of KOH remaining in the solution after the neutralization reaction is complete
First, we will determine the number of moles of each reactant present
For H₂SO₄Volume = 22.36 mL = 0.02236 L
Concentration = 0.142 M
From the formula,
Number of moles = Concentration × Volume
∴ Number of moles of H₂SO₄ = 0.142 × 0.02236
Number of moles of H₂SO₄ = 0.00317512 moles
For KOHVolume = 46.21 mL = 0.04621 L
Concentration = 0.304 M
∴ Number of moles of KOH = 0.304 × 0.04621
Number of moles of KOH = 0.01404784 moles
(NOTE: This is equal to the number of moles of OH⁻ at the beginning of the reaction)
From the equation of reaction, we have that
1 mole of H₂SO₄ will neutralize 2 moles KOH
Therefore,
0.00317512 moles of H₂SO₄ will neutralize 2×0.00317512 moles KOH
2×0.00317512 = 0.00635024 moles
This means only 0.00635024 moles of KOH reacted
(NOTE: This is equal to the number of moles of OH⁻ that reacted)
Now, for the number of moles of unreacted OH⁻
Number of moles of unreacted OH⁻ = Total number of moles OH⁻ at the beginning of the reaction - Number of moles of OH⁻ that reacted
∴ Number of moles of unreacted OH⁻ = 0.01404784 moles - 0.00635024 moles
Number of moles of unreacted OH⁻ = 0.0076976 moles
Number of moles of unreacted OH⁻ ≅ 0.00770 moles OR 7.70×10⁻³ moles
Hence, the number of moles of OH⁻ that are unreacted in the solution after the neutralization is complete is 0.00770 moles OR 7.70×10⁻³ moles
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Chlorophyll is found in
A. neither plant
nor animal cells.
B. animal cells.
C. plant cells.
D. plant and animal cells.
Answer:
Only plant cells
Explanation:
This organelle helps plants photosynthesize. Humans do not do that.
According to the following reaction, how many grams of sulfur are formed when 37.4 g of water are formed?
2H₂S(g) + SO₂(g) → 3S(s) + 2H₂O(l)
Answer:
Mass = 100.8 g
Explanation:
Given data:
Mass of sulfur formed = ?
Mass of water formed = 37.4 g
Solution:
Chemical equation:
2H₂S + SO₂ → 3S + 2H₂O
Number of moles of water:
Number of moles = mass/molar mass
Number of moles = 37.4 g/ 18 g/mol
Number of moles = 2.1 mol
Now we will compare the moles of water and sulfur.
H₂O : S
2 : 3
2.1 : 3/2×2.1 = 3.15
Mass of sulfur:
Mass = number of moles × molar mass
Mass = 3.15 mol × 32 g/mol
Mass = 100.8 g
A buffer solution is made that is 0.347 M in H2C2O4 and 0.347 M KHC2O4.
1. If Ka for H2C2O4 is 5.90E^-2, what is the pH of the buffer solution?
b. Write the net ionic equation for the reaction that occurs when 0.070 mol KOH is added to 1.00 L of the buffer solution.
Answer:
1. pH = 1.23.
2. [tex]H_2C_2O_4(aq) +OH^-(aq)\rightarrow HC_2O_4^-(aq)+H_2O(l)[/tex]
Explanation:
Hello!
1. In this case, for the ionization of H2C2O4, we can write:
[tex]H_2C_2O_4\rightleftharpoons HC_2O_4^-+H^+[/tex]
It means, that if it is forming a buffer solution with its conjugate base in the form of KHC2O4, we can compute the pH based on the Henderson-Hasselbach equation:
[tex]pH=pKa+log(\frac{[base]}{[acid]} )[/tex]
Whereas the pKa is:
[tex]pKa=-log(Ka)=-log(5.90x10^{-2})=1.23[/tex]
The concentration of the base is 0.347 M and the concentration of the acid is 0.347 M as well, as seen on the statement; thus, the pH is:
[tex]pH=1.23+log(\frac{0.347M}{0.347M} )\\\\pH=1.23+0\\\\pH=1.23[/tex]
2. Now, since the addition of KOH directly consumes 0.070 moles of acid, we can compute the remaining moles as follows:
[tex]n_{acid}=0.347mol/L*1.00L=0.347mol\\\\n_{acid}^{remaining}=0.347mol-0.070mol=0.277mol[/tex]
It means that the acid remains in excess yet more base is yielded due to the effect of the OH ions provided by the KOH; therefore, the undergone chemical reaction is:
[tex]H_2C_2O_4(aq) +OH^-(aq)\rightarrow HC_2O_4^-(aq)+H_2O(l)[/tex]
Which is also shown in net ionic notation.
Best regards!
How many moles of CO are produced when 1.8 moles C reacts?
Express your answer using two significat figures.
5C(s) + 2SO2(g) => CS2(l) +4CO(g)
Answer:
1.44mole of CO
Explanation:
The reaction equation is given as:
5C + 2SO₂ → CS₂ + 4CO
We check to see if the expression is balanced and it is so;
Now;
Given;
1.8mole of C reacted; how many moles of CO are produced;
From the balanced reaction equation:
5 mole of C is expected to produce 4 mole of CO
1.8 mole of C will then produce [tex]\frac{4 x 1.8}{5}[/tex] = 1.44mole of CO
Select the best answer from the choice below. When the wavelength decreases, the frequency:
Answer:
Increases
Explanation:
Frequency and wavelength of lights are inversely proportional to each other.
The wave of light having highest frequency have shortest wavelength and the light with the shortest frequency having highest wavelength.
Formula:
Speed of light = wavelength × frequency
c = λ × f
λ = c/f
This formula shows that both are inversely related to each other.
The speed of light is 3×10⁸ m/s
Frequency is taken in Hz.
It is the number of oscillations, wave of light make in one second.
Wavelength is designated as "λ" and it is the measured in meter. It is the distance between the two crust of two trough.
If 15.5 mL of 0.225 M aqueous magnesium chloride is added to 37.5 mL of 0.250 M aqueous lead(II) nitrate, then what mass of lead(II) chloride precipitates?A. 0.485 g.B. 0.971 g.C. 1.94 g.D. 3.888 g.E. 5.82 8 g.
Answer:
B. 0.971 g
Explanation:
When MgCl₂(aq) reacts with Pb(NO₃)₂(aq), PbCl₂(s) and Mg(NO₃)₂(aq) are produced:
MgCl₂(aq) + Pb(NO₃)₂(aq) →, PbCl₂(s) + Mg(NO₃)₂(aq)
Thus, we need to find imiting reactant finding moles of each reactant:
Moles MgCl₂:
15.5mL = 0.0155L * (0.225 mol / L) = 3.49x10⁻³ moles
Moles Pb(NO₃)₂:
37.5mL = 0.0375L * (0.250mol / L) = 9.38x10⁻³ moles
As the ratio of the reactants is 1:1, the moles of PbCl₂ are 3.48x10⁻³ moles.
We need to convert thes moles to mass using molar mass of PbCl₂ (278.1g/mol), thus:
3.48x10⁻³ moles * (278.1g/mol) =
0.968g of PbCl₂ are precipitate
Thus, right answer is:
B. 0.971 gamu.
An atom with 4 protons, 5 neutrons, and 4 electrons has an atomic mass of
(Enter a whole number.)
Answer:
Explanation:
the sum of number of proton and neutron is known as atomic mass
so if number of proton is 4 and neutron is 5 then atomic mass of an atom is 9
If the temperature of the water inside of the
pressure cooker is greater than 104'C, and the
water is still a liquid, then the pressure inside of the
pressure cooker must be
less than 1 atm
equal to 1 atm
c.
greater than 1 atm
Answer:
(C). Greater than 1atm
Explanation:
We are aware that water boils at 100 degree Celsius. Water can change its phase and become vapor at 100degree Celsius and at normal pressure which is 1atm.
In the given scenario we have enough temperature to convert water into vapor phase but we don't want it rather we want it to remain in liquid state. This can be achieved by increasing the pressure which was earlier required for vapor phase conversion. So the pressure should be greater than 1atm.
When we increase the temperature the molecules will get enough energy to escape into vapor phase, but when we will increase the pressure, it will provide hindrance to those molecules and will maintain them into Liquid state.
The bond lengths of the X-H bonds in CH4, SiH4, and SnH4 are 1.09, 1.48, and 1.71 Å, respectively. Estimate the length of the Ge-H bond in GeH4. Which of these four hydrides has the weakest X-H bond?Estimated Ge-H bond length =________________ ÅWeakest X-H bond in ________________
Answer:
what
Explanation:what
Help ASAP
Please and thank you
Answer: C
Explanation: Everything else is true.
Ice, H2O(s), is classified as: An ionic compound, a molecular compound, a homogeneous mixture, a heterogeneous mixture
Answer:
A molecular compound.
Explanation:
An ionic compound is composed of both metal and non-metal elements. Oxygen and hydrogen are both non-metal elements.Any mixture (no matter if it is homogeneous or heterogeneous) is composed of two or more compounds.Ice is simply water in solid form, so it is only one compound. Hence the answer is A molecular compound.Ice, H2O(s), is classified as ; ( B ) A molecular compound
Given that Ice and H₂O are the same element but in different forms therefore we can classify Ice, H₂O as been a molecular compound.
Ice and H₂O are not ionic compounds because ionic compounds are formed between metal and non-metal elements while H₂O and Ice are neither metals but are both Nonmetals
Hence we can conclude that Ice, H2O(s), is classified as A molecular compound
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can someone put this in other words Conduct an investigation to explore the use of Punnett squares to predict genotypes and phenotypes of offspring.
In the image below if the frisbee represents lights, what does the fence represent?
Answer:
The atmosphere
Explanation:
It reflects and traps the light outside of the Earth's Atmosphere?
I think, hope i helped.
The mass of 900. atoms of sodium(Na)
Answer:
3.44 × 10⁻²⁰ g Na
General Formulas and Concepts:
Chemistry - Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:
Step 1: Define
900 atoms Na
Step 2: Identify Conversions
Avogadro's Number
Molar Mass of Na - 22.99 g/mol
Step 3: Convert
[tex]900 \ atoms \ Na(\frac{1 \ mol \ Na}{6.022 \cdot 10^{23} \ atoms \ Na} )(\frac{22.99 \ g \ Na}{1 \ mol \ Na} )[/tex] = 3.4359 × 10⁻²⁰ g Na
Step 4: Check
We are given 3 sig figs. Follow sig fig rules and round.
3.4359 × 10⁻²⁰ g Na ≈ 3.44 × 10⁻²⁰ g Na
an ionic bond forms when atoms blank electrons
Answer:
An ionic bond forms when atoms transfer electrons.
Explanation:
Ionic bonds are formed when atoms transfer electrons. (In contrast, covalent bonds are formed when atoms share electrons.)
There's a distinction between the two: when two atoms react to form an ionic bond, one atom would completely lose one electron, while the other would completely gain that electron. The atom that loses the electron becomes a positively-charged ion called a cation, whereas the atom that gains the electron becomes a negatively-charged ion called an anion.
For example, consider the reaction between a sodium [tex]\rm Na[/tex] atom and a chlorine [tex]\rm Cl[/tex] atom: [tex]\rm Na + Cl \to NaCl[/tex].
When the sodium atom and the chlorine atom encounter, the sodium atom would lose one electron to form a positively-charged sodium ion, [tex]\rm Na^{+}[/tex]. The chlorine atom would gain that electron to form a negatively-charged chlorine ion [tex]\rm Cl^{-}[/tex].
These two ions will readily attract each other because of the opposite electrostatic charges on them. This electrostatic attraction (between two ions of opposite charges) is an ionic bond.
Overall, it would appear as if the sodium [tex]\rm Na[/tex] atom transferred an electron to the chlorine [tex]\rm Cl[/tex] atom to form an ionic bond.
In contrast, when two atoms react to form a covalent bond, they share electrons without giving any away completely. Therefore, it is possible to break certain covalent bonds apart (using a beam of laser, for example) and obtain neutral atoms.
On the other hand, when an ionic bond was broken, the result would be two charged ions- not necessarily two neutral atoms. The electron transfer could not be reversed by simply breaking the bond.
For example, when table salt [tex]\rm NaCl[/tex] is melted (at a very high temperature,) the ionic bond between the sodium ions and chloride ions would (mostly) be broken. However, doing so would only generate a mixture of [tex]\rm Na^{+}[/tex] and [tex]\rm Cl^{-}[/tex] ions- not sodium and chlorine atoms.
Answer:yea it’s transfer
Explanation:
Which element has the lowest first ionization energy?
NEED ASAP
Select one:
a. 1s22s22p63s23p5
b. 1s22s1
c. 1s22s22p63s23p6
d. 1s22s22p63s1
Answer:
C
Explanation:
there is no explanation needed
Answer:
The value of ionization energy (IE) decreases down the group due to the increasing size as the valence electrons are more loosely bound. Thus lowest IE in this case is of Bi as it is bottom most element.
Explanation:
If a horse travels 20 meters in 5 seconds what is the horses speed
distance = speed * time
speed = distance / time
speed = 20 meters / 5 seconds
speed = 4 meters / second
hope this helped!
Which of the following is NOT a property of gases?
Your answer:
A.They are easy to compress.
B.They expand to fill their containers.
C.They have a definite shape and a definite volume.
D.They occupy far more space than the liquids or solids from which they form.
Answer: C
Explanation:
A. As they do not have a given shape and expand to fill the container, modifying the size of the container modifies the space the gas occupies
B. They are nearly free molecules, which means no bound between them, moving fast and freely around the container
C. NOT A PROPERTY. As said before, as there are no bindings between molecules and move freely, they cannot have a fixed size cause they're always on the move.
D. Because they expand to fill the container, it's easy to them to occupy more space than in any other state, as the container is the only thing that defines how much volume they occupy
What is the concentration of chloride ions in a solution that contains 0.375 g of aluminum chloride in 15.0 mL of solution?
Answer:
0.561 M
Explanation:
Step 1: Given data
Mass of aluminum chloride (m): 0.375 gMolar mass of aluminum chloride (M): 133.34 g/molVolume of the solution (V): 15.0 mLStep 2: Calculate the molar concentration of aluminum chloride (C)
We will use the following expression.
[tex]C = \frac{m}{M \times V(L) } = \frac{0.375g}{133.34 g/mol \times 0.0150L } = 0.187M[/tex]
Step 3: Write the reaction of dissociation of aluminum chloride
AlCl₃(aq) ⇒ Al³⁺(aq) + 3 Cl⁻(aq)
Step 4: Calculate the concentration of chloride ions
The molar ratio of AlCl₃ to Cl⁻ is 1:3. The concentration of Cl⁻ is 3/1 × 0.187 M = 0.561 M
Aluminum metal reacts with hydrochloric acid according to the following equation:
2 A l left parenthesis s right parenthesis plus 6 H C l left parenthesis a q right parenthesis rightwards arrow 2 A l C l subscript 3 left parenthesis a q right parenthesis plus 3 H subscript 2 left parenthesis g right parenthesis
If 28.1 grams of aluminum reacts with 46 mL of a 1 M HCl solution, how many grams of AlCl3 will be generated? Hint: You must determine the limiting reactant
Answer:
18 g
Explanation:
Step 1: Write the balanced equation
2 Al + 6 HCl ⇒ 2 AlCl₃ + 3 H₂
Step 2: Calculate the moles of Al
The molar mass of Al is 26.98 g/mol.
28.1 g × 1 mol/26.98 g = 1.04 mol
Step 3: Calculate the moles of HCl
46 mL of 1 M HCl react.
0.046 L × 1 mol/L = 0.046 mol
Step 4: Determine the limiting reactant
The theoretical molar ratio of Al to HCl is 2:6 = 0.33:1.
The real molar ratio of Al to HCl is 1.04:0.046 = 22.6:1
According to this, the limiting reactant is HCl.
Step 5: Calculate the mass of AlCl₃ generated from 0.046 moles of HCl
The molar ratio of HCl to AlCl₃ is 6:2. The molar mass of AlCl₃ is 133.34 g/mol.
0.046 mol HCl × 6 mol HCl/2 mol AlCl₃ × 133.34 g AlCl₃/1 mol AlCl₃ = 18 g AlCl₃
Which of the following statement best defines matter?
Give the location in the Periodic Table of Elements that have the same number of electron shells
all columns (groups) have the same number of shells
all periods (rows) have the same number of shells
only the transition metal elements have the same number of shells
Group VIII
Explanation:
All period have the same number of shells
What is the work function of gold metal in kJ/mol if light with λ = 234 nm is necessary to eject electrons?
Answer
512kj/mole
Explanation:
What is the work function of gold metal in kJ/mol if light with λ = 234 nm is necessary to eject electrons?
The energy can be calculated using below expresion;
E = hc/λ
Where h= planks constant= 6.626 x 10^-34
c= speed of light= 3 x 10^
λ= wavelength
hc= (6.626 x 10^-34 x 3 x 10^ 8)
=
plz help ❤️
Explain how the pH of water has a synergistic relationship with other substances.
Provide an example.
Answer:
Explanation:
he pH of the water will determine the toxic effects, if any, of these substances.
Pure water is neutral with the pH of 7. But when water combines with other substance the pH varies as per the acidity of the combining substance.
What is pH?pH is the measure of acidity of a solution and mathematically it is the negative logarithm of hydrogen ion concentration. Acidic substance have a pH of less than 7 whereas, basic substance have higher pH value.
Water when combines with some acids, its acidity increases. For example acid rain resulting from the reaction of rain water with oxides of nitrogen and Sulphur forming nitric acid and sulphuric acid.
pH of water have a role in the toxic effects of components in water pH and alkalinity of water determines the coagulation of other substances in water.
Hence, the properties of other substance in water is pH dependent and might effect the alkalinity or acidity of water as well the properties of substances in water such as toxicity.
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In which orbitals would the valence electrons for selenium (Se) be placed?
Answer:
Valence electrons of selenium will be placed in s and p-orbitals.
Explanation:
Hope this helps.