Answer:
a little less than 109.5°
Explanation:
SCl2 has four regions of electron density around the central atom of the molecule. This implies that it has a tetrahedral electron domain geometry with an expected bond angle of 109.5° according to valence shell electron pair repulsion theory.
However, there are two lone pair of electrons on the central atom of the molecule which decreases the bond angle a little less than 109.5° owing to repulsion between electron pairs.
Classify each of the following as a strong acid or a weak acid and indicate how each should be written in aqueous solution. Classify ... In solution this acid should be written as: weak 1. hydrocyanic acid H3O CN- _______ 2. hydrobromic acid
Answer:
HCN, weak acid
H⁺, Br⁻, strong acid
Explanation:
Hydrocyanic acid is a weak acid, according to the following equation.
HCN(aq) ⇄ H⁺(aq) + CN⁻(aq)
Thus, it should be written in the undissociated form (HCN).
Hydrobromic acid is a strong acid, according to the following equation.
HBr(aq) ⇒ H⁺(aq) + Br⁻(aq)
Thus, it should be written in the ionic form (H⁺, Br⁻).
The energy levels of hydrogenlike one-electron ions of atomic number Z differ from those of hydrogen by a factor of Z^2. Predict the wavelength of the 2s--->1s transition in He+.
Answer:
[tex]\mathbf{\lambda \simeq 3.039 \times 10^{-8} \ m}[/tex]
Explanation:
For a hydrogen-like atom, the spectral line wavelength can be computed by using the formula:
[tex]\bar v = Z^2 R_H \Big(\dfrac{1}{n_f^2}-\dfrac{1}{n_i^2}\Big)[/tex]
where:
emitted radiation of the wavenumber [tex]\bar v[/tex] = ???
atomic no of helium Z = 2
Rydberg's constant [tex]R_H = 1.097*10^7 \ m^{-1}[/tex]
the initial energy of the principal quantum [tex]n_1[/tex] = 2
the initial energy of the principal quantum [tex]n_1[/tex] = 2
Now, the emitted radiation of the wavenumber can be computed as:
[tex]\bar v = (2)^2 (1.097*10^7 \ m^{-1} ) \Big(\dfrac{1}{1^2}-\dfrac{1}{2^2}\Big)[/tex]
[tex]\bar v = 3.291 \times 10^ 7/m[/tex]
Now, the wavelength for the transition can be computed by using the relation between the wavelength λ and the emitted radiation of the wavenumber [tex]\bar v[/tex], which is:
[tex]\bar v = \dfrac{1}{\lambda}[/tex]
[tex]\lambda = \dfrac{1}{\bar v}[/tex]
[tex]\lambda = \dfrac{1}{3.291 \times 10^{7}}\times \dfrac{m}{1}[/tex]
[tex]\mathbf{\lambda =3.03859 \times 10^{-8} \ m}[/tex]
[tex]\mathbf{\lambda \simeq 3.039 \times 10^{-8} \ m}[/tex]
Why the catalytic and optical properties of nanomaterial are different from bulk material
Answer:
The material properties of nanostructures are different from the bulk due to the high surface area over volume ratio and possible appearance of quantum effects at the nanoscale. ... Yu; they found that the structural distortions on the quantum dots depend both on the kind of dopant and on the size of the dots.
Explanation:
hope it helps
A 0.50 mol sample of COBr2 is transferred to a 9.50-L flask and heated until equilibrium is attained. Calculate the equilibrium concentrations of each species.
Answer:
Equlibrium concentration for each species ae as follows:
[CO] = 0.043 mol/L
[Br₂] = 0.043 mol/L
[COBr₂] = 0.01 mol/L
Explanation:
Let take a look at the chemical equation taking place at equilibrium
COBr2(g) ⇄ CO(g) + Br2(g)
The concentration of COBr2 i.e.
[COBr2] = no of moles/volume
= 0.50 mol/9.50 L
[COBr2] = 0.0530 mol/L
At standard conditions
Kc for COBr2 = 0.190
Now, the ICE table for the above reaction can be computed as follows:
COBr2(g) ⇄ CO(g) + Br2(g)
Initial 0.053 0 0
Change -x +x +x
Equilibrium (0.053 - x) x x
[tex]\mathsf{K_c = \dfrac{[CO][Br_2]}{[COBr_2]}}[/tex]
[tex]K_c = \dfrac{(x) (x)}{(0,053 -x)}[/tex]
[tex]0.190= \dfrac{x^2}{(0.053 -x)}[/tex]
x² = 0.190(0.053 - x)
x² = 0.01007 - 0.190x
x² + 0.190x - 0.01007 = 0
Using quadratic formula:
x ≅ 0.043 mol/L
SInce: x = [CO][Br₂] = 0.043 mol/L
[COBr₂] = 0.053 - x
[COBr₂] = 0.053 - 0.043 mol/L
[COBr₂] = 0.01 mol/L
Underneath the ocean floor, methane can exist as a solid known as methane hydrate. Methane hydrate forms when large amounts of methane become trapped in the crystal structure of water, which develops into a solid similar to ice. A scientist working for a deep water drilling company is studying the properties of the three different phases of methane: methane hydrate, liquified natural gas, and natural gas. Which of the properties is true
Answer:
Methane is present in solid, liquid and gaseous form.
Explanation:
Methane hydrate is present in solid state when the hydrogen-bonded water and methane gas come into contact at high pressures and low temperatures in the deep oceans while on the other hand, methane which is present inside the earth surface in gaseous form due to non-availability of water that can combine with methane. Methane is also found in liquid form when it is cool with high pressure and low temperature.
A compound was analyzed and found to contain 76.57% carbon, 6.43% hydrogen, and 17.00% oxygen by mass. Calculate the empirical formula of the compound. If the molar mass of the compound is 94.11 g/mol, what is the molecular formula of the compound?
A second compound is composed of 53.30% Carbon 11.19% Hydrogen and 35.51% Oxygen by mass.Please Calculate the empirical formula of the compound of the molar mass of the compound is 90.12g/mol, what is the molecular formula for that compound?
Answer:
See explanation
Explanation:
First we divide the percentage by mass of each element by it's relative atomic mass then we divide the quotients obtained by the lowest ratio obtained in the first step.
C- 76.57/12, H= 6.43/1, O = 17.00/16
C- 6.38/1.06, H= 6.43/1.06, O= 1.06/1.06
C- 6, H- 6, O- 1
Empirical formula: C6H6O
[(12 ×6) + (6 × 1) + (16 × 1)]n=94.11
[72 + 6 +16]n = 94.11
n = 94.11/94
n= 1
Molecular formula = C6H6O
2)
C- 53.30/12, H- 11.19/1, O- 35.51/16
C- 4.44/2.22, H- 11.19/2.22, O- 2.22/2.22
C- 2, H- 5, O- 1
Empirical formula: C2H5O
[(2×12) + (5× 1) + (1×16)]n = 90.12
[24 + 5 + 16] n = 90.12
n= 90.12/45
n= 2
Molecular formula = C4H10O2
There is a type of algae that lives in the cells of corals. These algae process carbon through photosynthesis and pass it on to corals in the form of glucose, a sugar that provides the energy corals need to survive and function. Corals offer protection for the algae and also produce wastes that the algae need for photosynthesis.
Warmer water temperatures caused by global warming disrupt photosynthesis in the algae, causing a poisonous build-up that threatens corals. This causes corals to force the algae out of their cells.
Answer:
Explanation:
Sample Response: If global warming continues, corals will continue to expel the algae from their cells to avoid poisonous buildup. This will cause corals to die. Without corals, the algae are not protected and cannot perform photosynthesis. This will cause the algae to die as well.
Determine the kinds of intermolecular forces that are present in each element or compound. Part A KrKr Check all that apply. Check all that apply. dispersion forces dipole-dipole forces hydrogen bonding
Answer:
The kinds of intermolecular forces that are present in each element Kr-Kr.
Explanation:
Since Kr is an inert gas and in atomic form only it is highly stable.
So, Kr gas does not form molecules.
Between the atoms of inert gas, there exist London dispersion forces.
Hence, the intermolecular forces that are present between Kr-Kr atoms is London dispersion forces.
if a=1/2(a+b)h,express a in terms of A,b and h. pls solve with step by step
Answer:
[tex] a = \frac {2A - bh}{h} [/tex]
Explanation:
Given the following mathematical expression;
A = ½(a + b)h
To make a the subject of formula (express a in terms of A, b and h);
First of all, we would cross-multiply;
2A = (a + b)h
Opening the bracket, we have;
2A = ah + bh
Rearranging the mathematical expression, we have;
ah = 2A - bh
[tex] a = \frac {2A - bh}{h} [/tex]
A 3.0-liter sample of an ideal gas is at a pressure of 2.5 atm at 15oC. (i) How many moles of gas are in the sample? (ii) If the volume does not change, what is the pressure of the gas when the temperature is 50oC?
Explanation:
here are the answers. Note that because the pressure is constant, you can use Gay Lussac's formula
The metal tantalum becomes superconducting at temperatures below 4.483 K. Calculate the temperature at which tantalum becomes superconducting in degrees Celsius.
Answer:
The correct answer is "-268.667°C".
Explanation:
Given:
Temperature,
= 4.483 K (below)
Now,
The formula of temperature conversion will be:
⇒ [tex]T(^{\circ} C)=T(K)-273.15[/tex]
By putting the values, we get
⇒ [tex]=4.483-273.15[/tex]
⇒ [tex]=-268.667^{\circ} C[/tex]
Thus the above is the correct answer.
The length of a covalent bond depends upon the size of the atoms and the bond order.
a. True
b. False
Answer:
True
Explanation:
The length of covalent bond depends upon the size of atoms and the bond order.
what is the qualitative analysis of (nh4) 2co3 using NaOH, HCL, BaCL2, and AgNO3
Answer:
qualatatiev is fs-hj_jakakak
༒How much does the earth weigh?☆☆☆☆☆☆☆☆☆☆☆☆
Answer:
Earth has a mass of 5.9736×1024 kg
5.972×10²⁴kghope it is helpful to you
Ammonia and oxygen react to form nitrogen monoxide and water. Construct your own balanced equation to determine the amount of NO and H2O that would form when 2.78 mol NH3 and 5.19 mol O2 react.
Answer:
The amount of NO formed s 2.78 moles or 83.4 grams
The amount of H2O formed is 4.17 moles or 75.1 grams
Explanation:
Step 1: Data given
Ammonia = NH3
Oxygen = O2
nitrogen monoxide = NO
water = H2O
Number of moles NH3 = 2.78 moles
Number of O2 = 5.19 moles
Step 2: The balanced reaction
4NH3 + 5O2 → 4NO + 6H2O
Step 3: Calculate moles of products
For 4 moles NH3 we need 5 moles O2 to produce 4 moles NO and 6 moles H2O
NH3 is the limiting reactant
All the NH3 will react. There will be 0 moles of NH3 left
For 4 moles NH3 we need 5 moles O2
For 2.78 moles NH3 we need 5/4 * 2.78 = 3.475 moles
There will be left 5.19 - 3.475 = 1.715 moles O2
For 4 moles NH3 we need 5 moles O2 to produce 4 moles NO and 6 moles H2O
For 2.78 moles NH3 we'll have 2.78 moles NO and 6/4 * 2.78 = 4.17 moles H2O
Step 4: Calculate mass of NO and H2O
Mass = moles * molar mass
Mass NO = 2.78 moles * 30.01 g/mol
Mass NO = 83.43 grams
Mass H2O = 4.17 moles * 18.02 g/mol
Mass H2O = 75.14 grams
The amount of NO formed s 2.78 moles or 83.4 grams
The amount of H2O formed is 4.17 moles or 75.1 grams
13. What would you expect the pH of an aqueous solution of tertiary bromide in water to be (acidic, neutral, or basic)
Answer:
oshfjidgshsjdh
Explanation:
918474828
determine the number of atoms of H in 35.0 grams of C2H4O2
Answer:
1.40x10^24 atoms of H
Explanation:
Which of the following is an alkaline earth metal?
A Carbon
B aluminum
C magnesium
D silicon
Answer:
Magnesium.
Explanation:
Because it is in group II
The speed of light_____ meters per second
☛ 299,792,458 meters per second.
A scientist is conducting a Sanger's sequencing experiment to determine the number of polypeptides present in an oligomeric protein. The molecular weight of the protein is 18000 g/mol . After the reaction of 520 mg of the protein with 1‑fluoro‑2,4‑dinitrobenzene, the peptide bonds were hydrolyzed with an acid. As a result, the scientist obtained 39 mg of 2,4‑dinitrophenyl serine. What is the number of the polypeptide chains present in the oligomer?
Answer:
Depends on molecule.
Explanation:
The number of the polypeptide chains present in the oligomer depends on the molecule. Some molecules have more polypeptide chains whereas some of them have less polypeptide chains. For example, Hemoglobin is a oligomer that consists of four Polypeptide Chains, two of these Polypeptide Chains are α-globin molecules, each comprise of 141 amino acids, and the other two are (β, γ, δ, or ε) globins, each consist of 146 amino acids.
Excited sodium atoms may emit radiation having a wavelength of 589nm. a) What is the wavelength in meters
Answer: When excited sodium atoms may emit radiation having a wavelength of 589nm. It's wavelength in meters is [tex]589 \times 10^{-9} m[/tex].
Explanation:
Given: Wavelength = 589 nm
It is known that,
[tex]1 nm = 10^{-9} m[/tex]
Hence, 589 nm is converted into meters as follows.
[tex]589 nm = 589 nm \times \frac{10^{-9}m}{1 nm}\\= 589 \times 10^{-9} m[/tex]
Thus, we can conclude that when excited sodium atoms may emit radiation having a wavelength of 589nm. It's wavelength in meters is [tex]589 \times 10^{-9} m[/tex].
define saturated and unsaturated fats
Explanation:
Saturated fats are defined as the fat where fatty acid chains contain only single bonds.
For example, stearic acid, palmitic acid etc.
Unsaturated fats are defined as the fat where fatty acids contain one or more number of double bonds on the carbon atoms.
For example, oleic acid, palmitoleic acid etc.
Write the balanced half-equations for silver + oxygen= silver oxide:
Answer: The balanced half-equations for silver + oxygen= silver oxide are:
Oxidation-half reaction: [tex]Ag \rightarrow 2Ag^{+} + 2e^{-}[/tex]
Reduction-half reaction: [tex]O_{2} + 2e^{-} \rightarrow 2O^{-}[/tex]
Explanation:
The word equation is as follows.
silver + oxygen = silver oxide
In terms of chemical formulas this equation can be written as follows.
[tex]Ag + O_{2} \rightarrow Ag_{2}O[/tex]
The removal on electron(s) from an atom, ion or molecule in a chemical reaction is called oxidation.
The gain of electron(s) by an atom, ion or molecule in a chemical reaction is called reduction.
Hence, half-reaction equations for the given reaction is as follows.
Oxidation-half reaction: [tex]Ag \rightarrow 2Ag^{+} + 2e^{-}[/tex]
Reduction-half reaction: [tex]O_{2} + 2e^{-} \rightarrow 2O^{-}[/tex]
As the number of atoms participating in the reaction are equal. Hence, the half-equations are balanced.
Thus, we can conclude that the balanced half-equations for silver + oxygen = silver oxide are:
Oxidation-half reaction: [tex]Ag \rightarrow 2Ag^{+} + 2e^{-}[/tex]
Reduction-half reaction: [tex]O_{2} + 2e^{-} \rightarrow 2O^{-}[/tex]
Analysis of an unknown substance showed that it has a high boiling point and is brittle. It is an insulator as a solid but conducts electricity when melted. Which of the following substances would have those characteristics?
a. HCl
b. Al
c. SiF4
d. KBr
e. I2
Answer:
The correct option is D (KBr)
Explanation:
Potassium bromide (KBr) is a typical example of an IONIC CRYSTAL. Positive and negative ions are arranged in a regular pattern to give a giant crystal lattice in an ionic solid.
Ionic crystals are hard and have high melting points because the electrostatic forces holding the ions are strong. In the solid state, ionic compounds are poor conductors of electricity because the ions are held rigidly in place and so cannot moves about.
When melted or when dissolved in water, the ions are free to move about and the ionic substances become good conductors of electricity.
Ionic crystals are also BRITTLE. When struck, they tend to shatter because as planes of ions slip by one another, they pass from a condition of mutual attraction to one of mutual repulsion.
According to the following pKa values listed for a set of acids, which would lead to the strongest conjugate base?
a. -2.
b. 1.
c. 7.
d. 25.
e. 50.
What effect would a decrease in volume have on pressure, assuming that temperature (T) and moles of gas (n) are kept constant
Answer:
Pressure increases
Explanation:
Boyle's law states that; '' the volume of a given mass of ideal gas is inversely proportional to its pressure at constant temperature.
Hence, when the volume of a given mass of ideal gas is decreased, the molecules of the gas come closer together so they collide with each other and the walls of the container more frequently.
This implies that the pressure of the gas increases as volume decreases in accordance with Boyle's law.
The products obtained from hydroboration-oxidation of cis-2-butene are identical to the products obtained from hydroboration-oxidation of trans-2-butene. Draw the products and explain why the configuration of the starting alkene is not relevant in this case.
Answer:
a) Attached below
b) The presence of racemic mixture found as product in both cases shows that products are identical ( i.e. they have same configuration
Explanation:
Diagrams of the products obtained from hydroboration-oxidation of cis-2-butene , hydroboration-oxidation of trans-2-butene.
attached below
The presence of racemic mixture found as product in both cases shows that products are identical ( i.e. they have same configuration )
the question is in the attachment
Answer:
About redox reaction which of the given statements are true?
Explanation:
Redox reaction is the one in which both oxidation and reduction reactions take place simultaneously.
For example:
[tex]C(s)+O_2(g)->CO_2(g)[/tex]
In this reaction, carbon undergoes oxidation and oxygen undergoes reduction simultaneously.
During this reaction, mutual exchange of electrosn take place between the oxidant and the reductant.
Among the given options,
Option B. electrons are transferred
and
option C.They include both oxidation and reduction takes place are the correct answers.
Ice and water constitute a system:
A Chemically heterogeneous and physically heterogeneous
B Chemically homogeneous and physically heterogeneous
C Chemically homogeneous and physically homogeneous
D Chemically heterogeneous and physically homogeneous
E None of the above
Answer:
B
Explanation:
It's the same substance but in different states.
HETEROGENEOUS mixtures contain substances that are
not uniform in composition. The parts in the mixture can be separated by physical means.
When 2.50 moles of oxygen reacts with excess hydrogen gas how many grams of water is
produced?
2 H2 + O2--> 2 H20
Answer:
90grams
Explanation:
The reaction given in this question is as follows:
2H2 + O2 → 2H20
Based on this equation, 1 mole of oxygen gas (O2) produces 2 moles of water (H2O)
Hence, 2.50moles of oxygen gas will react with excess hydrogen gas to produce (2.5 × 2) = 5.0moles of water.
Using mole = mass/molar mass
Molar mass of water (H2O) = 1(2) + 16
= 18g/mol
5 = mass/18
mass = 18 × 5
mass of H2O = 90grams
