Answer:
White phosphorusRed PhosphorusIt is insoluble in water but soluble in carbon disulphide.It is insoluble in both water and carbon disulphide.It undergoes spontaneous combustion in air.It is relatively
Explanation:
I hope it will help you
What reaction would cause a decrease in entropy?
Answer:
B
Explanation:
liquids is produce therefore it will have the less Entropy
Answer:
B.
Explanation:
if the # of molecules (of gas) on the product side is less than # of molecules on the reactant side = entropy is decreasing, and vice versa.
if the # of molecules on the reactant side is less than # of molecules on the product side = entropy is increasing (it is more disorderly, chaotic)
A. 2 → 2 + 1 entropy increases
B. 1 + 4 → 1 + 1 entropy decreases
C. 2 → 1 + 3 entropy increases
D. 2 + 1 → 2 + 2 entropy increases
Identify acceptable names for the molecule. A benzene ring with two bromine atoms attached at different sites of the ring, so that either three carbon atoms or one carbon atom separate them, depending on the direction from which you count from a bromine atom.
Answer:
1,3-dibromobenzene
Explanation:
An image of the compound described in the question is attached to this answer.
We need to reiterate here the rules of IUPAC nomenclature. The substituents in a compound must be named in such a way that they have the lowest number.
The compound described may also be named as 1,5-dibromobenzene but this name is disallowed because it gives the substituents a higher number than 1,3-dibromobenzene.
what is the difference between a chemical bonds formed in the molecules of 02 and the chemical bonds formed in crystals of a NaCI
Answer:
O2 is a covalent substance while NaCl is an ionic substance
Explanation:
In O2 molecule, the bond is between 2 oxygen atoms which are non - metals. Thus, this is a covalent bond since it involves 2 non metals.
Whereas, for the NaCl molecule, the bond is between a metal sodium (Na) and a non metal Chloride(Cl) and thus we can say this is an ionic bond.
Thus the difference is that O2 is a covalent substance while NaCl is an ionic substance.
Which of the following is the best definition of a physical change?
A. Ice melting into water.
B. A change that occurs without changing the identity of the substance.
C. Something that can be observed or measured while changing the identity of the substance.
D. A nail rusting.
If you eluted a TLC of a compound using 60% hexanes / 40% ethyl acetate as the solvent and obtained an Rf value of 0.5. If you changed the solvent system to 30% hexanes / 70% ethyl acetate, how would the Rf value change
Answer:
The Rf value change will be > 0.5
Explanation:
Given that Change in Solvent is proportional to change in polarity of solvent system
The change from solvent composition of 60/40 to 30/70 will cause an increase in the polarity of the system .
and Increase in Polarity = Increase in Rf value because the compound will move to a higher distance
Use dimensional analysis to solve the following problems. Pay attention to correct use of units and correct use of significant figures in calculations. Please show work!
Convert 3.00 x 10^21 atoms of copper to moles.
Convert 2.25 x 10^18 molecules of carbon dioxide to moles.
Answer:
1) 0.00498 mol Cu.
2) 0.00000374 mol CO₂
Explanation:
Question 1)
We want to convert 3.00 * 10²¹ copper atoms into moles. Note that 3.00 is three significant figures.
Recall that by definition, one mole of a substance has exactly 6.022 * 10²³ amount of that substance. In other words, we have the ratio:
[tex]\displaystyle \frac{1\text{ mol}}{6.022\times 10^{23} \text{ Cu}}[/tex]
We are given 3.00 * 10²¹ Cu. To cancel out the Cu, we can multiply it by our above ratio with Cu in the denominator. Hence:
[tex]\displaystyle 3.00 \times 10^{21} \text{ Cu} \cdot \frac{1\text{ mol Cu}}{6.022\times 10^{23} \text{ Cu}}[/tex]
Cancel like terms:
[tex]=\displaystyle 3\times 10^{21} \cdot \frac{1\text{ mol Cu}}{6.022\times 10^{23} }[/tex]
Simplify:
[tex]\displaystyle = \frac{3\text{ mol Cu}}{6.022 \times 10^{2}}[/tex]
Use a calculator:
[tex]= 0.004981... \text{ mol Cu}[/tex]
Since the resulting answer must have three significant figures:
[tex]= 0.00498\text{ mol Cu}[/tex]
So, 3.00 * 10²¹ copper atoms is equivalent to approximately 0.00498 moles of copper.
Question 2)
We want to convert 2.25 * 10¹⁸ molecules of carbon dioxide into moles. Note that 2.25 is three significant digits.
By definition, there will be 6.022 * 10²³ carbon dioxide molecules in one mole of carbon dioxide. Hence:
[tex]\displaystyle \frac{6.022 \times 10^{23} \text{ CO$_2$}}{1\text{ mol CO$_2$}}[/tex]
To cancel the carbon dioxide from 2.25 * 10¹⁸, we can multiply it by the above ratio with the carbon dioxide in the denominator. Hence:
[tex]\displaystyle 2.25\times 10^{18} \text{ CO$_2$} \cdot \frac{1\text{ mol CO$_2$}}{6.022\times 10^{23} \text{ CO$_2$}}[/tex]
Cancel like terms:
[tex]\displaystyle= 2.25\times 10^{18} \cdot \frac{1\text{ mol CO$_2$}}{6.022\times 10^{23}}[/tex]
Simplify:
[tex]\displaystyle = \frac{2.25 \text{ mol CO$_2$}}{6.022\times 10^5}}[/tex]
Use a calculator:
[tex]=0.000003736...\text{ mol CO$_2$}[/tex]
Since the resulting answer must have three significant figures:
[tex]= 0.00000374\text{ mol CO$_2$}[/tex]
So, 2.25 * 10¹⁸ molecules of carbon dioxide is equivalent to approximately 0.00000374 moles of carbon dioxide.
Answer:
Explanation:
by definition, 1 mole contains 6.02 x 10^23 of atoms (for elements) or molecules (for compounds)
3.00 x 10^21 atoms of copper / 6.02 x 10^23 of atoms
= 0.004983 moles of copper
= 4.98 x 10^(-3) moles of copper
2.25 x 10^18 molecules of carbon dioxide / 6.02 x 10^23 of molecules
= 0.000003737 moles of carbon dioxide
= 3.74 x 10^(-6) moles of carbon dioxide
Why are prefixes not needed in naming ionic compounds?
Answer:
when naming ionic compounds — those are only used in naming covalent molecular compounds. Do NOT use prefixes to indicate how many of each element is present; this information is implied in the name of the compound. since iron can form more than one charge. Ionic Compounds Containing a Metal and a Polyatomic Ion.
Gaseous BF3 and BCl3 are mixed in equal molar amounts. All B-F bonds have about the same bond enthalpy, as do all B-Cl bonds. Compare the numbers of microstates to explain why the mixture tends to react to form BF2Cl(g) and BCl2F(g
Solution :
[tex]$BF_3 (g) + BCl_3 (g) \rightarrow BF_2 Cl + BCl_F(g)$[/tex]
Explanation 1 :
Spontaneity of the reaction is based on two factors :
-- the tendency to acquire a state of minimum energy
-- the energy of a system to acquire a maximum randomness.
Now, since there isn't much difference in the bond enthalpies of B-F and B-Cl. So, we can say the major driving factor is tendency to acquire a state of maximum randomness.
Explanation 2 :
A system containing the [tex]\text{"chemically mixed"}[/tex] B halides has a [tex]\text{greater entropy}[/tex] than a system of [tex]$BCl_3$[/tex] and [tex]BF_3[/tex].
It has the same number of [tex]\text{gas phase molecules}[/tex], but more distinguishable kinds of [tex]\text{molecules}[/tex], hence, more microstates and higher entropy.
How many atoms are present in 0.45 moles of P4010
Answer:
80g
Explanation:
mass oxygen present in 1 mole of p4010
16×10=160gm
similarly
for 0.5 moles of p4010 160/2= 80gm
The number of atoms present in 0.45 moles of P₄O₁₀ is 1.08 x 10²³ atoms.
To determine the number of atoms, we use Avogadro's number, which states that there are approximately 6.022 x 10²³ particles (atoms, molecules, or formula units) in one mole of a substance.
In this case, we are given 0.45 moles of P₄O₁₀. To calculate the number of atoms, we multiply the number of moles by Avogadro's number:
Number of atoms = 0.45 moles P₄O₁₀ x (6.022 x 10²³ atoms / 1 mole)
Number of atoms = 2.7139 x 10²³ atoms
Rounding to three significant figures, the number of atoms present in 0.45 moles of P₄O₁₀ is approximately 1.08 x 10²³ atoms.
To learn more about atoms here
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The density of mercury is 13.6 g/cm3, What is its density in mg/mm3?
Answer:
Density of mercury is 13600 kg
A hypothetical A-B alloy of composition 53 wt% B-47 wt% A at some temperature is found to consist of mass fractions of 0.5 for both and phases. If the composition of the phase is 92 wt% B-8 wt% A, what is the composition of the phase
Answer:
the composition of the ∝ phase C∝ = 14 or [ 14 wt% B-86 wt% A ]
Explanation:
Given the data in the question;
Co = 53 or [ 53 wt% B-47 wt% A ]
W∝ = 0.5 = Wβ
Cβ = 92 or [ 92 wt% B-8 wt% A ]
Now, lets set up the Lever rule for W∝ as follows;
W∝ = [ Cβ - Co ] / [ Cβ - C∝ ]
so we substitute our given values into the expression;
0.5 = [ 92 - 53 ] / [ 92 - C∝ ]
0.5 = 39 / [ 92 - C∝ ]
0.5[ 92 - C∝ ] = 39
46 - 0.5C∝ = 39
0.5C∝ = 46 - 39
0.5C∝ = 7
C∝ = 7 / 0.5
C∝ = 14 or [ 14 wt% B-86 wt% A ]
Therefore, the composition of the ∝ phase C∝ = 14 or [ 14 wt% B-86 wt% A ]
What type of bond does hafnium oxide have?
A. ionic
B. covalent
C. Metallic
Answer:
C) METALLIC IS THE CORRECT ANSWER
Explanation: I just did the exam
Classify each molecule as an alcohol, ketone, or aldehyde based on its name. Propanone (acetone) Choose... Ethanal Choose... 3-phenyl-2-propenal Choose... Butanone Choose... Ethanol Choose... 2-propanol Choose...
Answer:
1.) Propanone (ketone)
2.) Ethanal( aldehyde)
3.) 3-phenyl-2-propenal (aldehyde)
4.) Butanone (ketone)
5.) Ethanol ( alcohol)
6.) 2-propanol (alcohol)
Explanation:
In organic chemistry, ALCOHOL ( also known as alkanol) are compounds in which hydroxyl groups are linked to alkyl groups. They can be considered as being derived from the corresponding alkanes by replacing the hydrogen atoms with hydroxyl groups. The hydroxyl group is the functional group of the alcohol as it is responsible for their characteristic chemical properties. A typical example of alcohol is ethanol and 2-propanol.
Alkanals or ALDEHYDES have the general formula RCHO while alkanones or KETONES have the general formula RR'CO where R and R' may be alkyl or aryl groups. The main similarity between these two classes of compounds is the presence of the carbonyl group. In aldehydes, there is a hydrogen atom attached to the carbon In the carbonyl group while there is none on the ketones.
Some common examples of ketones are Propanone, Butanone while examples of aldehydes are Ethanal and 3-phenyl-2-propenal
When 250. mg of eugenol, the molecular compound responsible for the odor of oil of cloves, was added to 100. g of camphor, it lowered the freezing point of camphor by 0.62 8C. Calculate the molar mass of eugenol.
Answer:
Molar mass for eugenol is 161.3 g/mol
Explanation:
This question talks about freezing point depression:
Our solute is eugenol.
Our solvent is camphor.
Formula to state the freezing point depression difference is:
ΔT = Kf . m . i where
ΔT = Freezing T° of pure solvent - Freezing T° of solution
In this case ΔT = 0.62°C
Kf for camphor is: 37°C /m
As eugenol is an organic compund, i = 1. No ions are formed.
To state the molar mass, we need m (molal)
Molal are the moles of solute in 1kg of solvent. Let's replace data:
0.62°C = 40 °C/m . m . 1
0.62°C / 40 m/°C = 0.0155 m
We convert mass of camphor from g to kg = 100 g . 1kg / 1000g = 0.1 kg
0.0155 molal = moles of solute / 0.1 kg
0.0155 m/kg . 0.1 kg = 0.00155 moles
We know that these moles are contained in 250 mg, so the molar mass will be:
0.25 g / 0.00155 mol = 161.3 g/mol
Notice, we convert mg to g, for the units!
Predict the reactants of this chemical reaction.
products: KClO4 + H2O
reactants: ?
Answer:
KOH + HClO4 = K(ClO4) + H2O
Explanation:
KClO4 + H2O : mix and match the letters if you need to guess
A threatened species is _____.
the same as an endangered species
A) threatened with becoming extinct in the near future
B) the same as an extinct species
C) one that could become endangered soon
Answer:
i think this is a biology question but regardless a threatened species is same as endangered which is going to become extinct in the near future but i say the best answer is threatened with becoming extinct in the near future.
An enzyme increases the reaction rate by:________. a. stabilizing of transition state. b. shifting the reaction equilibrium. c. increasing the probability of product formation. d. All of the answers are correct. e. None of the answers is correct.
(c) m X is an ion in which group of the periodic table is the element from which X is formed?
Explanation:
Iron has 2 atoms and 3atoms.
So,X=2,3
Which daughter element is produced from the alpha decay of 213 over 85 At ?
A. 213 over 86 Rn
B.217 over 87 Fr
C. 213 over 84 Po
D. 209 over 83 Bi
Answer:
209
83 Bi
Explanation:
213 213 - 4 4
85 At = 85 - 2 Y + 2 He
Cho một thực phẩm có độ ẩm tương đối là 81%, hỏi hoạt độ của nước trong thực phẩm đó là
Given question is:
Given a food with a relative humidity of 81%, what is the water activity in that food?
Explanation:
Water activity in food can be determined by using the below-shown formula:
[tex]water activity=\frac{equilibrium relative humidity}{100}[/tex]
Equilibrium is established between the vapor pressure of food and the surrounding air media.
Thus, for the given food the relative humidity is 81%.
hence, its water activity is
[tex]81/100\\=0.81[/tex]
What force is behind us when we ride a bike?
Answer:
gravity, ground, friction, rolling resistance, and air resistance.
Determine the empirical formula of a compound containing 47.37 grams of carbon, 10.59 grams of hydrogen, and 42.04 grams of oxygen.
In an experiment, the molar mass of the compound was determined to be 228.276 g/mol. What is the molecular formula of the compound?
For both questions, show your work or explain how you determined the formulas by giving specific values used in calculations. (10 points)
Answer:
Mass of C = 47.37g
Mass of H = 10.59g
Mass of O = 42.04g
The total mass of these elements is 100g, taking a proportion of their molar masses.
C = 47.37/12= 3.95
H = 10.59/1 = 10.59
O = 42.04/16= 2.63.
Dividing through with the smallest proportion which is 2.63
C=3.95/2.63 = 1.5
H =10.59/2.63 =4
O = 2.63/2.63= 1
Multiplying through by 2 to get a whole number.
C = 1.5x2 = 3
H= 4x2 = 8
O = 1x2= 2
The empirical formula is C3H6O2
(Empirical formula)n= molecular mass
(C3H8O2)n =228.276
(12x3 +8+16x2)n= 228.276
76n = 228.276
n = 228.276/76
n = 3
Molecular formula = Empirical formula
=(C3H8O2)3 = C9H24O6
The molecular formula is C9H24O6
10.0 g of Mg are reacted with 95.0 g of I2. If 27.5 g of magnesium iodide are obtained, what is the percent yield
Answer:
% yield of reaction is 26.4
Explanation:
The reaction is:
Mg + I₂ → MgI₂
Our reactants are magnessium and iodine. We determine the moles of each to find the limiting reactant:
10 g . 1mol / 24.3 g = 0.411 moles of Mg
95 g . 1mol / 253.8g = 0.374 moles of I₂
Ratio is 1:1. For 1 mol of Mg we need 1 mol of iodine
For 0.411 moles, we need the same amount, but we only have 0.374 moles of iodine, that's why the gas is the limiting reactant.
As ratio is 1:1 again, 0.374 moles of iodine can produce 0.374 moles of MgI₂
We determine the mas (theoretical yield): 0.374 mol . 278.1 g/mol = 104 g
To calculate the percent yield:
% yield = (yield produced /theoretical yield) . 100
% yield = (27.5 g/ 104g) . 100 = 26.4
Methane gas and chlorine gas react to form hydrogen chloride gas and carbon tetrachloride gas. What volume of hydrogen chloride would be produced by this reaction if of methane were consumed
Answer:
4.4 mL
Explanation:
Methane gas and chlorine gas react to form hydrogen chloride gas and carbon tetrachloride gas. What volume of hydrogen chloride would be produced by this reaction if 1.1 mL of methane were consumed?
Step 1: Write the balanced equation
CH₄(g) + 4 Cl₂(g) ⇒ 4 HCl(g) + CCl₄(g)
Step 2: Establish the appropriate volume ratio
For gases under the same conditions, the volume ratio is equal to the molar ratio. The molar ratio of CH₄ to HCl is 1:4.
Step 3: Calculate the volume of HCl produced from 1.1 mL of CH₄
1.1 mL CH₄ × 4 mL HCl/1 mL CH₄ = 4.4 mL HCl
8moles of Na2Cr2O2 is how much mass
[tex] \boxed{\boxed{\mathfrak{ 1\: mole \:of \:Na_2Cr_2O_2\: = \:it's \:Gram\: Mol. \: mass}} }[/tex]
[tex]\underline{ \mathfrak{ Gram \:molecular \:mass \:of \: \red{ Na_2Cr_2O_2}}}[/tex]
= 2 × 23 + 2 × 52 + 2 × 16
= 182 grams
1 mole of [tex]Na_2Cr_2O_2[/tex] weighs = 182 g
8 moles weigh = 8× 182
=[tex] \mathfrak{\blue {\boxed{\underline {1456 \: grams}}}} [/tex]
or
[tex] \mathfrak{\blue {\boxed{\underline {1. 46 \:kg }}}} [/tex]
once formed, how are coordinate covalent bonds different from other covalent bonds?
Answer:
[tex]\boxed {\boxed {\sf {One \ atom \ donates \ both \ electrons \ in \ a \ pair}}}[/tex]
Explanation:
A covalent bond involves the sharing of electrons to make the atoms more stable, and so they satisfy the Octet Rule (8 valence electrons).
Typically each atom contributes an electron to form an electron pair. This is a single bond. There are also double bonds (two pairs of electrons), triple bonds (three pairs of electrons), and coordinate covalent bonds.
Sometimes, to satisfy the Octet Rule and achieve stability, one atom contributes both of the electrons in an electron pair. This is different from other covalent bonds because usually each of the 2 atoms contributes an electron to make a pair.
Which intermolecular force plays a pivotal role in biological molecules such as proteins and DNA ?
•hydrogen bonding
•dispersion force
•dipole-dipole force
•Ion-dipole force
Answer:
hydrogen bonding
Explanation:
just took the test :D
In the given range,at what temperature does oxy gen have the highest solubility?
A student prepares a aqueous solution of acetic acid . Calculate the fraction of acetic acid that is in the dissociated form in his solution. Express your answer as a percentage. You will probably find some useful data in the ALEKS Data resource.
Answer:
10.71%
Explanation:
The dissociation of acetic acid can be well expressed as follow:
CH₃COOH ⇄ CH₃COO⁻ + H⁺
Let assume that the prepared amount of the aqueous solution is 14mM since it is not given:
Then:
The I.C.E Table is expressed as follows:
CH₃COOH ⇄ CH₃COO⁻ + H⁺
Initial 0.0014 0 0
Change - x +x +x
Equilibrium (0.0014 - x) x x
Recall that:
Ka for acetic acid CH₃COOH = 1.8×10⁻⁵
∴
[tex]K_a = \dfrac{[x][x]]}{[0.0014-x]}[/tex]
[tex]1.8*10^{-5} = \dfrac{[x][x]]}{[0.0014-x]}[/tex]
[tex]1.8*10^{-5} = \dfrac{[x]^2}{[0.0014-x]}[/tex]
[tex]1.8*10^{-5}(0.0014-x) = x^2[/tex]
[tex]2.52*10^{-8} -1.8*10^{-5}x = x^2[/tex]
[tex]2.52*10^{-8} -1.8*10^{-5}x - x^2 =0[/tex]
By rearrangement:
[tex]- x^2 -1.8*10^{-5}x +2.52*10^{-8}= 0[/tex]
Multiplying through by (-) and solving the quadratic equation:
[tex]x^2 +1.8*10^{-5}x-2.52*10^{-8}= 0[/tex]
[tex](-0.00015 + x) (0.000168 + x) =0[/tex]
x = 0.00015 or x = -0.000168
We will only consider the positive value;
so x=[CH₃COO⁻] = [H⁺] = 0.00015
CH₃COOH = (0.0014 - 0.00015) = 0.00125
However, the percentage fraction of the dissociated acetic acid is:
[tex]= \dfrac{ 0.00015}{0.0014}\times 100[/tex]
= 10.71%
Which particle has a mass of 9.11 x 10^-28g and charge of -1?
A. electron
B. proton
C. neutron
QUESTION:- Which particle has a mass of 9.11 x 10^-28g and charge of -1?
OPTIONS:-
A. electron
B. proton
C. neutron
ANSWER:-
CHARGE ON PROTRON IS +1 AND IT HAS MASS OF [tex]1.6 \times 10 {}^{ - 27} [/tex] SO IT CANNOT BE URE ANSWER
THERE IS NO CHARGE ON NEUTRON AND HAS MASS ALMOST EQUAL TO THE PROTON SO IT ALSO CANNOT BE URE ANSWER
MASS OF THE ELECTRON:- [tex]9.11 \times 10^{ - 28} [/tex]
CHARGE ON ELECTRON:- [tex] -1[/tex]
SO URE ANSWER IS ELECTRON
