Answer:
história phkfk
Explanation:
guiooupigjdytrss
characteristics of crystal
Answer:
Crystalline solids, or crystals, have distinctive internal structures that in turn lead to distinctive flat surfaces, or faces. The faces intersect at angles that are characteristic of the substance. When exposed to x-rays, each structure also produces a distinctive pattern that can be used to identify the material.
Explanation:
Compound EX4 reacts with Y2 giving two products: EX Y and XY. Calculate the E- X bond enthalpy if the reaction liberates 243.6 kJ/mol and other bond enthalpies are:
Y-Y 109 kJ/mol,
X-Y 123.1 kJ/mol and
E-Y 290 kJ/mol.
a. 547.7 kJ/mol
b. 60.5 kJ/mol
c. 234.7 kJ/mol
d. 20.6 kJ/mol
e. 176.9 kJ/mol
Answer:
Option B
Explanation:
From the question we are told that:
Equation
[tex]EX_4+Y_2->EX_3Y+XY[/tex]
Bond enthalpies are:
[tex]Y-Y 109 kJ/mol,[/tex]
[tex]X-Y 123.1 kJ/mol[/tex]
[tex]E-Y 290 kJ/mol.[/tex]
Generally the equation for the energy used to break E-X and Y-Y is mathematically given by
[tex]E_2=109+x[/tex]
Therefore
Total Energy Liberated is
[tex]E_T=E_1+E_2[/tex]
[tex]E_T=413.1+109+x[/tex]
[tex]E_T=304.1-x[/tex]
Since
[tex]E_T+E_I[/tex]
Therefore
[tex]304.1-x=243.6[/tex]
[tex]x=60.5kJ/mol[/tex]
Option B
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.
A student calculates the empirical formula of a compound to be C1.5H3.5. Express this as a correct empirical formula.
Answer:
No, the correct empirical formula is [tex]C_3H_7[/tex].
Explanation:
Hello there!
In this case, according to the given information, it turns out necessary for us to bear to mind the fact that empirical formulas must not be expressed in decimal numbers, for that reason, we need to multiply the given empirical formula by 2 to get the correct one:
[tex]C_3H_7[/tex]
Which is now possible.
Regards!
What is the major organic product obtained from the sequence of reactions 2-phenyl-4 bomobutane and NaN3?
Answer:
(E)-1-phenylbut-1-ene
Explanation:
2-phenyl-4 bromobutane is an amphetamine that contains a phenyl group. It forms a major stable product with other reacting agents.
The major organic product that is obtained from the sequence of the reactions of the 2-phenyl-4 bomobutane when it reacts with [tex]NaN_3[/tex] is the (E)-1-phenylbut-1-ene.
Thus the answer is 2-phenyl-4 bromobutane is an amphetamine that contains a phenyl group. It forms a major stable product with other reacting agents.
The major organic product that is (E)-1-phenylbut-1-ene.
Water supplies are treated with chlorine to kill pathogens. Chlorine reacts well with many other chemicals and bacterial cells because it is a strong oxidant. However, Legionella pneumophila can sometimes evade killing by residual chlorine. How does it do this
Answer:
By forming Biofilms
Explanation:
Legionella pneumophila forms biofilms by using the residual chlorine and hence act as killer of other microbial cells and intracellular pathogens. It also colonizes within multispecies microbial communities and kills them
4. An exothermic reaction is accompanied by a decrease in entropy. How would this reaction be
classified?
A. spontaneous at all temperatures
B. nonspontaneous only at low temperatures
C. nonspontaneous at all temperatures
D. spontaneous only at low temperatures
Answer:
Spontaneous at only low temperature. I made a chart for my AP Chem class if you want to refer to it.
Which of the following is true for the percentage yield of a reaction?
Answer:
It is always less than the theoretical yield.
In the following neutralization reaction, which substance is the acid?
HCI + NaOH - NaCl + H20
ОА.
НСІ
OB.
NaOH
OC.
NaCl
OD. H20
Answer:
HCl is a acid
Explanation:
NaOH is base
Nacl is salt
The specific heat capacity of liquid water is 4.18 J/g-K. How many joules of heat are needed to raise the temperature of 6.00 g of water from 36.0°C to 75.0 °C?
Answer:
978 J
General Formulas and Concepts:
Thermodynamics
Specific Heat Formula: q = mcΔT
q is heat (in J) m is mass (in g) c is specific heat (in J/g °C) ΔT is change in temperature (in °C)Explanation:
Step 1: Define
[Given] c = 4.18 J/g K
[Given] m = 6.00 g
[Given] ΔT = 75.0 °C - 36.0 °C = 39.0 °C
[Solve] q
Step 2: Find q
Substitute in variables [Specific Heat Formula]: q = (6.00 g)(4.18 J/g K)(39.0 °C)Multiply [Cancel out units]: q = 978.12 JStep 3: Check
Follow sig fig rules and round. We are given 3 sig figs.
978.12 J ≈ 978 J
Answer:
I don't remember this topic very well.
Explanation:
if we want to increase 1C° of 1 gram water. we must use 4.18 joules energy that 75-36= 39 C° for 6 gram H2O we should use 6*39*(4.18) joules
Which one is the ionic compound?
Answer:
NAF IS AN IONIC COMPOUND
Explanation:
Answer:
Explanation:
CO2 is a covalent bonding. It is something from the middle of the periodic table bonded with something on the right of the periodic table. It is not ionic.
NH3 is also covalent. The H bonds with the N and the H has properties that resemble both the metals and non metals. That's why it is on both the left and right sides of the periodic table. In this case, it is more non metallic than metallic. Since Nitrogen is on the right side of the table, you have a situation where 2 nonmetals are bonding. It is not ionic.
The answer is NaF. Sodium is on the left side of the periodic table and F is on the right side. That's what it takes to get an ionic bond.
Plz help!!!! NO LINKS
Answer:
481.16 cm³
Explanation:
From the question given above, the following data were obtained:
Height (h) = 11.72 cm
Diameter (d) = 7.23 cm
Pi (π) = 3.14159
Volume of cylinder (V) =?
Next, we shall determine the radius. This can be obtained as follow:
Diameter (d) = 7.23 cm
Radius (r) =?
r = d/2
r = 7.23 / 2
r = 3.615 cm
Finally, we shall determine the volume of the cylinder. This can be obtained as shown below:
Height (h) = 11.72 cm
Pi (π) = 3.14159
Radius (r) = 3.615 cm
Volume of cylinder (V) =?
V = πr²h
V = 3.14159 × 3.615² × 11.72
V = 3.14159 × 13.068225 × 11.72
V = 481.16 cm³
Therefore, the volume of the cylinder is 481.16 cm³.
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
2 AICI3 + 3 Ca - 3 CaCl2 + 2 Al
You react aluminum chloride with calcium metal. You want to produce 40.00 grams of aluminum. How many grams of calcium do you need?
Classification of igneous, sedimentary and metamorphic rocks is based on
A)Mineral assemblages and composition assemblages and composition
B)Appearance of the rock and texture
C)composition and mineral make-up
D)Texture and rock chemistry
Match each term with the best description.
a. The electrode where oxidation occurs
b. A device that produces electricity
c. The connection between two half-cells
d. The electrode where reduction occurs
e. A device that consumes electricity
f. A device that utilizes redox reactions to either consume or produce electricity
1. Anode
2. Cathode
3. Electrolytic cell
4. Electrochemical
5. Galvanic cell
6. Salt bridge
Answer:
Match each term with the best description.
a. The electrode where oxidation occurs: Anode
b. A device that produces electricity: Galvanic cell
c. The connection between two half-cells: salt bridge
d. The electrode where reduction occurs: Cathode
e. A device that consumes electricity: Electrolytic cell
f. A device that utilizes redox reactions to either consume or produce electricity: Electrochemical cell.
Explanation:
a.The electrode where oxidation occurs is called the anode.
Oxidation is losing of electrons.
b. Galvanic cell produces electricity by using redox chemical reaction.
It is also called a voltaic cell or electrochemical cell.
c. The connection between two cells is called a salt bridge.
It will not allow the solutions to diffuse with each other.
It maintains electrical neutrality.
d. The electrode where reduction occurs: Cathode
Reduction means the gaining of electrons.
e. Electrolytic cell is the one that consumes electricity and then produces a chemical change.
f. A device that utilizes redox reactions to either consume or produce electricity: Electrochemical cell.
Compound A, C8H10, absorbed 3 equivalents of H2 on catalytic hydrogenation over a Pd/C catalyst to give B (C8H16). On ozonolysis, compound A gave, among other things, a ketone which was identified as cyclopentanone. On treatment with NaNH2 in NH3, followed by addition of iodomethane, compound A gave a new hydrocarbon, C (C9H12). Draw the structure of Compound A and Compound B.
Answer:
Compound A, C8H10, absorbed 3 equivalents of H2 on catalytic hydrogenation over a Pd/C catalyst to give B (C8H16). On ozonolysis, compound A gave, among other things, a ketone which was identified as cyclopentanone. On treatment with NaNH2 in NH3, followed by addition of iodomethane, compound A gave a new hydrocarbon, C (C9H12). Draw the structure of Compound A and Compound B.
Explanation:
The degree of unsaturation in the given compound A C8H10 is:
DU= (Cn+1)-Hn/2 -Xn/2 +Nn/2
DU=(8+1)-10/2
=9-5
=4
So, the given compound has either three double bonds and a ring or four double bonds or four rings.
Given,
compound A C8H10 absorbed three equivalents of H2 on catalytic hydrogenation that means compound A has three double bonds or it has one double bond and one triple bond.
The structure of compounds A, B and C along with the entire reaction is shown below:
dfine chemical reaction
Answer:
A process that involves rearrangement of the molecular or ionic structure of a substance, as opposed to a change in physical form or a nuclear reaction.
Explanation:
Pretty much just not a physical reaction or otherwise
How does the magnetic force vary with distance
Answer:
Magnetic force obeys an inverse square law with distance. ... If the distance between two magnets is doubled the magnetic force between them will fall to a quarter of the initial value. (F/4) If the distance between two magnets is halved the magnetic force between them will increase to four times the initial value.
Which term describes atoms with
unpaired dots in their electron dot
diagrams?
Answer:
Radicals
Explanation:
A radical refers to a chemical specie that contains unpaired electrons in their dot electron diagrams.
Radicals contain an odd number of electrons. They are commonly called odd electron species.
Radicals participate in a number of important reactions. A typical example is the halogenation of alkanes in the presence of light.
Examples of radicals include; Br. , Cl. , F. etc
Determine the mass in grams of 3.27 × 10²¹ atoms of arsenic. (The mass of one mole of arsenic is 74.92 g.)
Explanation:
74.92 g.
(The mass of one mole of arsenic is 74.92 g.
Compound A has a partition coefficient (K) of 7 when comparing its solubility in CH2Cl2 to water ( K=11, [solubility of A in g/ml in CH2Cl2] divided by [solubility of A in g/ml in H2O]). If we take 17.0 g of A and partition it thoroughly between 150 ml of CH2Cl2 and 100 ml of water, what is the equation which will tell us how much of A (which is represented by x) is in the water layer after this partitioning ?
Answer:
The equation which will tell us how much of A that is mis inmthe water layer after partitioning is: 7 = (17 - x) g / 150 mL ÷ x g /100 mL
Explanation:
A partition coefficient is the ratio of the concentration of a substance in one solvent phase to the concentration in a second solvent phase when the two concentrations are at equilibrium. Usually the two phases are an organic phase and an aqueous phase. Thus, the partition coefficient K, of a compound is the ratio of the compound's concentration in the organic layer compared to the aqueous layer.
K = C₁/C₂ at equilibrium
In the compound A given, CH₂Cl₂ is the organic phase while water is the aqueous phase
Amount of A that is partitioned in between dichloromethane, CH₂Cl₂ and water, H₂O is 17.0 g
Let the amount of A that is dissolved in water be x g
Solubility of A in water given in g/mL = (x / 100) g/ml
Amount of A dissolved in dichloromethane, CH₂Cl₂ = (17 - x) g
Solubility of A in dichloromethane, CH₂Cl₂ given in g/mL = (17 - x/150) g/mL
Since the partition coefficient, K of compound A when comparing its solubility in CH₂Cl₂ to water is 7, that is;
K = [solubility of A in g/ml in CH₂Cl₂] / [solubility of A in g/ml in H2O] = 7
The equation for the amount of A in the water layer is given as follows:
7 = (17 - x) g / 150 mL ÷ x g /100 mL
Solving for x
7 = (17 -x) × 100 / 150x
7 × 150x = (17 - x) × 100
1050x = 1700 - 100x
1150x = 1700
x = 1700/1150
x = 1.48 g
How many moles of CO2 form when 4.0 mol of ethane, C2H6, react?
2C2H6 + 702 + 4CO2 + 6H20
A. 8 mol
B. 2 mol
C. 6 mol
D. 4 mol
Answer:
The amswer would be A due to the ratio between ethane and carbon dioxide being 1:2. Due to this, you double the moles that are reacting
No tires P ni basura al suelo
Answer:
no halbo ingles
Explanation:
Please help me name these organic compounds
Answer:
Aldehydes and Ketones
Both aldehydes and ketones contain a carbonyl group, a functional group with a carbon-oxygen double bond. The names for aldehyde and ketone compounds are derived using similar nomenclature rules as for alkanes and alcohols, and include the class-identifying suffixes -al and -one, respectively:

In an aldehyde, the carbonyl group is bonded to at least one hydrogen atom. In a ketone, the carbonyl group is bonded to two carbon atoms:


As text, an aldehyde group is represented as –CHO; a ketone is represented as –C(O)– or –CO–.
In both aldehydes and ketones, the geometry around the carbon atom in the carbonyl group is trigonal planar; the carbon atom exhibits sp2 hybridization. Two of the sp2 orbitals on the carbon atom in the carbonyl group are used to form σ bonds to the other carbon or hydrogen atoms in a molecule. The remaining sp2 hybrid orbital forms a σ bond to the oxygen atom. The unhybridized p orbital on the carbon atom in the carbonyl group overlaps a p orbital on the oxygen atom to form the π bond in the double bond.
Like the C=OC=O bond in carbon dioxide, the C=OC=O bond of a carbonyl group is polar (recall that oxygen is significantly more electronegative than carbon, and the shared electrons are pulled toward the oxygen atom and away from the carbon atom). Many of the reactions of aldehydes and ketones start with the reaction between a Lewis base and the carbon atom at the positive end of the polar C=OC=O bond to yield an unstable intermediate that subsequently undergoes one or more structural rearrangements to form the final product (Figure 1).
Figure 1. The carbonyl group is polar, and the geometry of the bonds around the central carbon is trigonal planar.
The importance of molecular structure in the reactivity of organic compounds is illustrated by the reactions that produce aldehydes and ketones. We can prepare a carbonyl group by oxidation of an alcohol—for organic molecules, oxidation of a carbon atom is said to occur when a carbon-hydrogen bond is replaced by a carbon-oxygen bond. The reverse reaction—replacing a carbon-oxygen bond by a carbon-hydrogen bond—is a reduction of that carbon atom. Recall that oxygen is generally assigned a –2 oxidation number unless it is elemental or attached to a fluorine. Hydrogen is generally assigned an oxidation number of +1 unless it is attached to a metal. Since carbon does not have a specific rule, its oxidation number is determined algebraically by factoring the atoms it is attached to and the overall charge of the molecule or ion. In general, a carbon atom attached to an oxygen atom will have a more positive oxidation number and a carbon atom attached to a hydrogen atom will have a more negative oxidation number. This should fit nicely with your understanding of the polarity of C–O and C–H bonds. The other reagents and possible products of these reactions are beyond the scope of this chapter, so we will focus only on the changes to the carbon atoms:
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.
Write the bond line formula for the compound (CH3)2CHCH2C(CH3)3.
Formula is (CH3)2CHCH2C(CH3)3 and the name is 2,2,4-trimethylpentane
A steel with a critical fracture toughness of 150 MPa.m1/2 has a yield strength of 1500 MPa. If fracture were to take place at the yield stress, answer the following questions.
Surface crack size at yielding leading to failure is:_____________.
a. 0.497 cm
b. 0.994 cm
c. 0.32 cm
Answer:
c.
Explanation:
From the given information:
Critical fracture toughness [tex]K_{IC}[/tex] = 150 MPa.[tex]m ^{1/2}[/tex]
yield strength [tex]\sigma[/tex] = 1500 MPa
surface crack size [tex]a_c[/tex] = ???
The formula for the fracture toughness is can be expressed as:
[tex]K_{IC}= \sigma \sqrt{\pi a_c}[/tex]
replacing our values to solve for the surface crack size, we have:
[tex]150= 1500 \sqrt{\pi a_c}[/tex]
[tex]\dfrac{150}{ 1500} = \sqrt{\pi a_c}[/tex]
[tex]\dfrac{0.1}{1.77} = \sqrt{ a_c}[/tex]
[tex]a_c[/tex] = 0.0564²
[tex]a_c[/tex] = 0.0032 m
[tex]a_c[/tex] = 0.32 cm
What is the definition of the molar mass of an element or compound?
Answer:
The molar mass is the mass of a given chemical element or chemical compound (g) divided by the amount of substance(mol) .
Explanation:
hope it may help you
mark as brainlist please
The molecular formula of water is H, O. What does it express
Answer:
Firstly, the molecular formula of water would be H2O. Secondly, it expresses the amount of different atoms in the water molecule. In this case, H2 would be two Hydrogen atoms, and O would be 1 Oxygen atom.
Explanation:
Hope this helped!
Answer:
It basically means that water contains 2 atoms of Hydrogen and 1 atom of Oxygen.
It also expresses that the valency of Oxygen is 2 and water has more Hydrogen than Oxygen