Answer:
It is D).cyclohexanone ( in acellus)
Explanation:
which effect of long-term environmental change is the driving force behind evolution?
Answer:
climate change
Explanation:
climate change is driving force of evolution because when the climate is changed the animal and human need to adapt to it's natural change.
Match each description below:
a. Will react with water.
b. Will react with steam or acid, but not water.
c. Will react with acid only
d. Will not tract with water, steam, or acid.
1. Cr
2. Cu
3. K
d. Sn
Answer:
a) will react with water: K
b) will react with steam or acid, but not water: Cr & Sn
d) will not react with water, steam, or acid: Cu
Explanation:
K reacts violently with water.
Cr will react with steam to form an oxide + H gas and will react with most acids
Sn will react with steam to form SnO₂ + H gas and, though it does not react as rapidly as other metals in acid, it dissolves easily in concentrated acids
Cu is an extremely nonreactive metal, which is what makes it so suitable for wiring
Place the following in order of increasing molar entropy at 298 K.
a. C3H8 < SO < CO2
b. CO2 < C3H8 < SO
c. C3H8 < CO2 < SO
d. SO < CO2 < C3H8
e. CO2 < SO < C3H8
Answer:
SO < CO2 < C3H8
Explanation:
Entropy refers to the degree of disorderliness of a system. The standard molar entropy of a substance refers to the entropy of 1 mole of the substance vunder standard conditions.
The molar entropy depends on the number of microstates in the system which in turn depends on the number of atoms in the molecule.
C3H8 has 11 atoms and hence the highest number of microstates followed by CO2 having three atoms and least of all SO having only two atoms.
How many milliliters of a 0.40%(w/v) solution of nalorphine must be injected to obtain a dose of 1.5 mg?
Answer:
0.375mL of solution of nalorphine must be injected
Explanation:
A solution of 0.40% (w/v) contains 0.40g of solute (In this case, nalorphine), in 100mL of solution. To obtain 1.5mg of nalorphine = 1.5x10⁻³g of nalorphine are needed:
1.5x10⁻³g * (100mL / 0.40g) =
0.375mL of solution of nalorphine must be injectedIn an experiment, you added a base, NaOH, one mL at a time to 50 mL acetate buffer and recorded the pH. For the first 6 mL NaOH the pH increased from 4.5 to 4.9. At the 7th mL the pH was 6.6 and by the 8th mL the pH was 10.7. Knowing what you do about titrating acetate buffer with acid, is this experimental result what you expected or is it not expected
Answer:
yes the experimental result is the expected result .
Explanation:
When Titrating acetate buffer with acid the PH will decrease gradually from a more neutral PH to a more acidic level and this is because buffer solutions are prepared with weak acids and its conjugate base.
The results gotten from the continuous addition of base NaOH to the acetate buffer is the expected result because the base is been absorbed by the buffer solution and it is converted to a conjugate base of the buffer solution which will gradually increase the PH level of the solution as more conjugate base is formed due to the addition of more NaOH.
Identify the Lewis acid and Lewis base from among the reactants in each of the following equations.
Part A
Ag+(aq)+2NH3(aq)⇌Ag(NH3)2+(aq)
a. Ag+ is the Lewis acid and NH3 is the Lewis base.
b. Ag+ is the Lewis base and NH3 is the Lewis acid.
Part B
AlBr3+NH3⇌H3NAlBr3
a. AlBr3 is the Lewis base and NH3 is the Lewis acid.
b. AlBr3 is the Lewis acid and NH3 is the Lewis base.
Part C
Cl−(aq)+AlCl3(aq)⇌AlCl4−(aq)
a. AlCl3 is the Lewis acid and Cl− is the Lewis base.
b. AlCl3 is the Lewis base and Cl− is the Lewis acid.
Answer:
Part A
Ag+ is the Lewis acid and NH3 is the Lewis base.
Part B
AlBr3 is the Lewis acid and NH3 is the Lewis base.
Part C
AlCl3 is the Lewis acid and Cl− is the Lewis base.
Explanation:
A Lewis acid is any specie that accepts a lone pair of electrons. Ag^+, AlBr3 and AlCl3 all accepted lone pairs of electrons according to the three chemical reaction equations shown. Hence, they are Lewis acids.
A Lewis base donates a lone pair of electrons. They include neutral molecules having lone pair of electrons such as NH3 or negative ions such as Cl- .
Which best expresses the uncertainty of the measurement 32.23 cm?
A.) ±0.05 cm
B.) 0.1 cm
C.) 1%
D.) ±0.01 cm?
Answer:
D.) ±0.01 cm?
Explanation:
Since 32.23 cm has two decimal places, the uncertainty is taken as one-half the last decimal pace.
The last decimal place is 0.03. Half of this is 0.03 cm/2 = 0.015 cm.
Since we cannot go below two decimal places, we ignore the 5 in 0.015 cm.
So, we have our uncertainty as 0.01 cm.
So, the best expression of the uncertainty in the measurement 32.23 cm is ± 0.01 cm.
So, the answer is D. which is ± 0.01 cm.
A tank at is filled with of sulfur tetrafluoride gas and of sulfur hexafluoride gas. You can assume both gases behave as ideal gases under these conditions. Calculate the mole fraction of each gas. Round each of your answers to significant digits.
The question is incomplete, the complete question is:
A 7.00 L tank at [tex]21.4^oC[/tex] is filled with 5.43 g of sulfur hexafluoride gas and 14.2 g of sulfur tetrafluoride gas. You can assume both gases behave as ideal gases under these conditions. Calculate the mole fraction and partial pressure of each gas. Round each of your answers to significant digits.
Answer: The mole fraction of sulfur hexafluoride is 0.221 and that of sulfur tetrafluoride is 0.779
Explanation:
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] ......(1)
For sulfur hexafluoride:Given mass of sulfur hexafluoride = 5.43 g
Molar mass of sulfur hexafluoride = 146.06 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of sulfur hexafluoride}=\frac{5.43g}{146.06g/mol}=0.0372mol[/tex]
For sulfur tetrafluoride:Given mass of sulfur tetrafluoride = 14.2 g
Molar mass of sulfur tetrafluoride = 108.07 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of sulfur tetrafluoride }=\frac{14.2g}{108.07g/mol}=0.1314mol[/tex]
Total moles of gas in the tank = [0.0372+ 0.1314] mol = 0.1686 mol
Mole fraction is defined as the moles of a component present in the total moles of a solution. It is given by the equation:
[tex]\chi_A=\frac{n_A}{n_A+n_B}[/tex] .....(2)
where n is the number of moles
Putting values in equation 2, we get:
[tex]\chi_{SF_6}=\frac{0.0372}{0.1686}=0.221[/tex]
[tex]\chi_{SF_4}=\frac{0.1314}{0.1686}=0.779[/tex]
Hence, the mole fraction of sulfur hexafluoride is 0.221 and that of sulfur tetrafluoride is 0.779
Consider an atom that has an electron in an excited state. The electron falls to a lower energy level. What effect does that have on the electron?
A.The electron releases energy in the form of light.
B.The electron absorbs energy in the form of light.
C.The electron retains its energy without any change.
D.The electron transfers its energy to other electrons.
Answer:
c it does not change the energy state
Explanation:
When an electron moves up to higher energy levels, the atom Choose... a photon of light whereas the atom Choose... a photon of light when an electron drops to a lower energy level. The photons emitted from an atom appear as
Answer:
Explanation:
When an electron moves from a lower energy level to a higher energy level, energy is absorbed by the atom. When an electron moves from a higher to a lower energy level, energy is released and photon is emitted.
this emitted photon is depicted as a small wave-packet being expelled by the atom in a well-defined direction.
how many moles of neon gas have a volume of 0.84 L and a pressure of 4.6 atm at 222k
Answer:
n = 0.21 moles
Explanation:
Given that,
Volume, V = 0.84 L
Pressure, P = 4.6 atm
T = 222 K
We need to find the number of moles of Neon gas. We know that,
PV = nRT
Where
n is the number of moles
R i the gas constant, R = 0.08206 L-atm/mol-K
Put all the values,
[tex]n=\dfrac{PV}{RT}\\\\n=\dfrac{4.6\times 0.84}{0.08206 \times 222}\\\\n=0.21\ \text{moles}[/tex]
So, there are 0.21 moles of Neon gas.
Identify the isoelectronic elements.
i. Cl-, F-, Br-, I-, At-
ii. Ne, Ar, Kr, Xe, He
iii. N3-, S2-, Br-, Cs+, Sr2+
iv. N3-, O2-, F-, Na+, Mg2+
v. Li+, Na+, K+, Rb+,Cs+
Answer:
iv. N³⁻, O²⁻, F⁻, Na⁺, Mg²⁺
Explanation:
Isoelectronic elements are those that have the same number of electrons. So, if at least 2 elements differ in their number of electrons, the series is not of isoelectronic elements.
To know the number of electrons we will consider the atomic number and add electrons if it is an anion and subtract electrons it is a cation.
Identify the isoelectronic elements.
i. Cl⁻, F⁻, Br⁻, I⁻, At⁻. NO. Cl⁻ has 18 electrons (17+1) and F⁻ has 10 electrons (9+1). ii. Ne, Ar, Kr, Xe, He. NO. Ne has 10 electrons and Ar has 18. iii. N³⁻, S²⁻, Br⁻, Cs⁺, Sr²⁺. NO. N³⁻ has 10 electrons (7+3) and S²⁻ has 18 (16+2).iv. N³⁻, O²⁻, F⁻, Na⁺, Mg²⁺. YES. They all have 10 electrons v. Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺. NO. Li⁺ has 2 electrons (3-1) and Na⁺ has 10 (11-1).
What would happen to the Earth's hydrosphere if there were no atmosphere?
Which of the following is considered a standard unit of length in the United States?
O square inch
O acre
O cubic yard
O yard
Answer:
Yard . I hope this helped:))
Sodium is a highly reactive metal and
chlorine is a toxic gas, but when they
come together the resulting material,
sodium chloride, is essential for life.
Which of the following is true when
sodium and chlorine are brought into
contact with one another?
Answer:
NaCl
Explanation:
[tex]na + cl > nacl[/tex]
This is also a salt
Can someone help me answer this please
Answer:
A) 1.3 × 10⁻⁵ mol/L
Explanation:
Step 1: Write the balanced equation for the solution of AgCl
AgCl(s) ⇄ Ag⁺(aq) + Cl⁻(aq)
Step 2: Make an ICE Chart
AgCl(s) ⇄ Ag⁺(aq) + Cl⁻(aq)
I 0 0
C +S +S
E S S
If we replace the solubility (S) in the Ksp expression, we get,
Ksp = [Ag⁺] [Cl⁻] = S × S = S²
S = √Ksp = √1.8 × 10⁻¹⁰ = 1.3 × 10⁻⁵ mol/L
A buffer solution contains 0.298 M ammonium chloride and 0.478 M ammonia. If 0.0560 moles of hydroiodic acid are added to 225 mL of this buffer, what is the pH of the resulting solution?
Answer:
pH = 8.87
Explanation:
Hydroiodic acid, HI, is a strong acid that reacts with ammonia, NH3, to produce ammonium ion, NH⁴⁺. That means the moles of HI added = moles of NH3 consumed and moles of NH4⁺ produced.
Initial moles NH₄⁺:
0.225L * (0.298mol/L) = 0.06705 moles
Initial moles NH3:
0.225L * (0.478mol/L) = 0.10755 moles
After the reaction the moles are:
0.10755moles NH3 - 0.0560moles = 0.05155 moles NH3
0.06705moles NH4+ + 0.0560moles = 0.12305 moles NH4+
Using H-H equation for weak bases:
pOH = pKb + log ([NH4+] / [NH3])
pKb for ammonia is 4.75, [NH4+] could be the moles of NH4+ = 0.12305mol,
[NH3] = 0.05155moles
Replacing:
pOH = 4.75 + log (0.12305mol / 0.05155moles)
pOH = 5.13
pH = 14-pOH
pH = 8.87If the Air Pressure on a mountain Is 0.3 atm what is this value mmHg? 1atm = 760mmHg = 101kPa
Answer:
IS IT MULTIPLE CHOICE
Explanation:
Can the properties of different substances in a mixture be used to separate them?
Answer: here you go
Explanation:
Physical properties of the substances in a mixture are different, so this allows the substances to be separated. Think about the example of a mixture of salt water.
Answer:
Mixtures can be classified on the basis of particle size into three different types: solutions, suspensions, and colloids. The components of a mixture retain their own physical properties. These properties can be used to separate the components by filtering, boiling, or other physical processes.
Explanation:
During a chemical reaction, an iron atom became the ion Fe2+. What happened to the iron atom?
Explanation:
Iron atom is been oxidised as it losses 2 electron to form 2 + ion.
g The boiling of water is a Question 4 options: chemical and physical damage chemical change because a gas (steam) is given off chemical change because heat is needed for the process to occur physical change because the water merely disappears physical change because the gaseous water is chemically the same as the liquid
Answer:
physical change because the gaseous water is chemically the same as the liquid
Explanation:
Matter can be defined as anything that has mass and occupies space. Any physical object that is found on earth is typically composed of matter. Matter are known to be made up of atoms and as a result has the property of existing in states.
Generally, matter exists in three (3) distinct or classical phases and these are; solid, liquid and gas.
A physical change can be defined as a type of change that only affects the physical form of a chemical substance (matter) without having any effect on its chemical properties. Thus, a physical change would only affect the physical appearance and properties of a chemical substance (matter) but not its chemical properties.
This ultimately implies that, a physical change result in a change of matter from one form or phase (liquid, solid or gas) to another without a corresponding change in chemical composition.
Hence, the boiling of water is considered to be a physical change because the gaseous water is chemically the same as the liquid i.e there isn't any changes in chemical composition of water when boiling.
explain why seeing a gas doesn not always indicate that there was a chemical change.
You pre-weigh a glass vial to hold your sample and find its mass to be 5.010 g. You add your sample to the vial and reweigh it on the same balance and find that the mass has increased to 6.130 g. What is the mass of the sample in grams
When we pre-weigh a glass vial to hold our sample and find its mass to be 5.010 g. Then we add our sample to the vial and reweigh it on the same balance and find that the mass has increased to 6.130 g. The mass of the sample in grams is 1.12 g.
What is mole concept?Avogadro's number is the number of units in one mole of any substance and equals to 6.02214076 × 10²³. The units can be electrons, atoms, ions, or molecules.
No. of moles is defined as a particular no. of particles that we can calculate with the help of Avogadro’s number.
Mass of a particular product is also find out by stoichiometry of a reaction as per the no. of mole given in the reaction.
Mass is generally can be represented by units like Kg, g etc.
Given,
weigh of glass vial = 5.010 g
weigh of glass vial with sample = 6.130 g
Therefore, When we pre-weigh a glass vial to hold our sample and find its mass to be 5.010 g. Then we add our sample to the vial and reweigh it on the same balance and find that the mass has increased to 6.130 g. The mass of the sample in grams is 1.12 g.
Learn more about mass, here:
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describe how lyophobic sols are synthesize by dispersion method
Explanation:
For preparing lyophobic sol, the substance in bulk is broken down into particles of colloidal dimensions (Dispersion) or aggregating smaller particles into particles of colloidal dimensions (condensation).
Predict the products from theses reaction, and balance the equations. Include phase symbols.
Reaction : K(s)+Cl2(g)⟶
Reaction :Cu(s)+O2(g)⟶
Answer:
2 K(s) + Cl₂(g) ⟶ 2 KCl(s)
2 Cu(s) + O₂(g) ⟶ 2 CuO(s)
Explanation:
Both reactions are synthesis reactions (two substances combine to form another).
Reaction: K(s) + Cl₂(g) ⟶
The product is the binary salt KCl. The balanced chemical equation is:
2 K(s) + Cl₂(g) ⟶ 2 KCl(s)
Reaction: Cu(s) + O₂(g) ⟶
The most likely product is the metal oxide CuO. The balanced chemical equation is:
2 Cu(s) + O₂(g) ⟶ 2 CuO(s)
There are four different starting molecules that one might use to synthesize the illustrated alkyl halide as the major product using an electrophilic addition reaction. Please draw all four of them.
Answer:
Explanation:
An electrophilic addition reaction occurs when an electrophile attacks a substrate, with the end result being the inclusion of one or many comparatively straightforward molecules along with multiple bonds.
In the given question, the hydrogen bromide provides the electrophile while the bromide is the nucleophile. The mechanism proceeds with the attack of the electrophile on the carbon, followed by deprotonation. This process is continued with a formation of carbocation and the bromide(nucleophile) finally bonds to the carbocation to form a stable product.
The first diagram showcases the possible various starting molecules for the synthesis while the second diagram illustrates their mechanism.
the mixture of base and acid
Answer:
Mixture of a Strong Acid and a Strong Base
On mixing a strong acid and strong base neutralization (pH = 7) takes place. The resulting solution may be an acid or base depending on the Concentration. Say, N1, V1 is the strength and volume of the strong acid and N2, V2 is the strength and volume of the strong base
Explanation:
Most introductory chemistry books will teach that the reaction between an acid and a base is called neutralization, and the products formed are water and a salt
What size volumetric flask would you use to create a 1.00M solution using 166.00 g of KI?
Answer:
A 1 liter volumetric flask should be used.
Explanation:
First we convert 166.00 g of KI into moles, using its molar mass:
Molar mass of KI = Molar mass of K + Molar mass of I = 166 g/mol
166.00 g ÷ 166 g/mol = 1 mol KIThen we calculate the required volume, using the definition of molarity:
Molarity = moles / litersLiters = moles / molarity
1 mol / 1.00 M = 1 Lwhat would be the mass of 44.8 L of CO2 gas at STP?
show work if possible
Answer:
[tex]m=88.02g[/tex]
Explanation:
Hello there!
In this case, for this ideal gas law problem, it turns out necessary for us to remember that one mole of any gas is contained in 22.4 L at STP and therefore, we can use the following ratio to calculate the moles in 44.8 L of CO2:
[tex]\frac{1mol}{22.4L} =\frac{x}{44.8L}\\\\x= \frac{1mol*44.8L}{22.4L}=2mol[/tex]
Finally, since the molar mass of CO2 is 44.01 g/mol, we calculate the mass as follows:
[tex]m=2mol*\frac{44.01g}{1mol}\\\\m=88.02g[/tex]
Regards!
Compare the solubility of calcium sulfite in each of the following aqueous solutions:
a. 0.10 M Ca(CH3COO)2
b. 0.10 M K2SO3
c. 0.10 M NaNO3
d. 0.10 M KCH3COO
1. More soluble than in pure water.
2. Similar solubility as in pure water.
3. Less soluble than in pure water.
Answer:
0.10 M Ca(CH3COO)2- Less soluble than in pure water.
0.10 M K2SO3- Less soluble than in pure water.
0.10 M NaNO3 - More soluble than in pure water.
0.10 M KCH3COO- Similar solubility as in pure water.
Explanation:
We have to cast our minds back to the idea of common ions effect. If any ion is already present in solution, the presence of that ion in solution prevents any solute containing a common ion with the solution from dissolving in that solution. In order words, the presence of a common ion makes a solute less soluble in a solvent than it is in pure water.
For instance, 0.10 M Ca(CH3COO)2 and K2SO3 both contain Ca^2+ and SO3^2- ions respectively which are also contained in the solute calcium sulfite.
The presence of these common ions in solution makes calcium sulfite less soluble in these solutions than it is in pure water because the equilibrium position for the dissolution of the solute lies towards the left hand side.
However, calcium sulfite is more soluble in 0.10 M NaNO3 than in pure water due to displacement reaction between the ions in solution.
The solubility of calcium sulfite and 0.10 M KCH3COO in pure water is quite comparable.