Among three bases, X−, Y−, and Z−, the strongest one is Y−, and the weakest one is Z−. Rank their conjugate acids, HX, HY, and HZ, in order of decreasing strength. Rank the acids from strongest to weakest. To rank items as equivalent, overlap them.
Answer: HZ > HX > HY in order of decreasing strengths.
Explanation: Generally, the rule is that the stronger the acid, the weaker its conjugate base and vice versa; same rule applies for bases and their conjugate acids.
So the weakest base Z- would have the strongest conjugate acid. Consequently, the strongest base Y- would have the weakest conjugate acid.
I hope this was MORE helpful as this is the correct answer.
The ranking of the conjugate acids in order of decreasing strength (i.e from strongest to weakest) is; HZ < HX < HY
First we must know that the stronger a base is, the weaker is it's conjugate acid and the weaker a base is, the stronger is it's conjugate acid.
Therefore, the order of decreasing strength of the conjugate acid is; HZ < HX < HY
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Enter an abbreviated electron configuration for magnesium: Express your answer in complete form, in order of increasing energy. For example, [He]2s22p2 would be entered as [He]2s^22p^2.
Answer:
[Ne]3s²
Explanation:
Mg
1s2 2s2 2p6 3s2 or [Ne]3s²
Abbreviated electronic configuration of magnesium is [Ne]3 s² and in complete form it is 1 s² 2 s² 2 p⁶ 3 s².
What is electronic configuration?Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.
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During lab, students mixed two solutions of soluble ions in a ceramic well to determine if a precipitate forms.
Write the dissolution reaction for the ionic solids below. (Use the lowest possible coefficients. Include states-of-matter under the given conditions in your answer.)
(a) Ca(NO3)2
(b) Na3PO4
The two solutions, when mixed, will have two cations and two anions.
(c) Based on your lab results, enter the cation and anion for which a precipitate will form. (Separate substances in a list with a comma.)
(d) Write the net precipitation reaction that occurs. (Use the lowest possible coefficients. Include states-of-matter under the given conditions in your answer.)
Answer:
(a) [tex]Ca(NO_3)_2(s)\rightarrow Ca^{2+}(aq)+2NO_3^-(aq)[/tex]
(b) [tex]Na_3PO_4(s)\rightarrow 3Na^++PO_4^{3-}[/tex]
(c) [tex]Ca^{2+} \ and \ PO_4^{3-}[/tex]
(d) [tex]3Ca^{2+}(aq)+2PO_4^{3-}(aq)\rightarrow Ca_3(PO_4)_2(s)[/tex]
Explanation:
Hello,
In this case, the balanced dissolution reactions are:
(a) [tex]Ca(NO_3)_2(s)\rightarrow Ca^{2+}(aq)+2NO_3^-(aq)[/tex]
(b) [tex]Na_3PO_4(s)\rightarrow 3Na^++PO_4^{3-}[/tex]
Moreover, when calcium nitrate and sodium phosphate react a double displacement reaction occurs, forming calcium phosphate, which is actually the precipitate due to its low solubility in water, and sodium nitrate:
[tex]2Na_3PO_4(aq)+3Ca(NO_3)_2(aq)\rightarrow 6NaNO_3(aq)+Ca_3(PO_4)_2(s)[/tex]
Thus, the precipitate is formed by:
(c) [tex]Ca^{2+} \ and \ PO_4^{3-}[/tex]
Finally, the net precipitation reaction shows the involved cation, anion and final product:
(d) [tex]3Ca^{2+}(aq)+2PO_4^{3-}(aq)\rightarrow Ca_3(PO_4)_2(s)[/tex]
Regards.
How have safety concerns about chemicals changed over time?
A. Government officials rather than scientists decide what chemicals
are dangerous.
B. All nations have agreed to a set of safety standards, so testing
chemicals is no longer necessary.
C. As scientists have learned more about chemicals, they have
become more aware of their dangers.
D. Scientists are no longer as concerned about chemicals because
they are much safer today.
Answer:
C. As scientists have learned more about chemicals, they have become more aware of their dangers
Explanation:
Chemicals are substances with standard compositions, held together by chemical bonds. Chemicals can exist in different phases such as solid, liquid, and gaseous phases. Over time, with a growing understanding of chemicals, their composition, and their reaction methods, scientists now have a better knowledge of the dangers chemicals can pose. To that effect, they have created standard safety measures for those who have to work with these chemicals.
When these guidelines are strictly adhered to, the chances of suffering accidents, burns, and explosions with these chemicals are significantly reduced.
Calculate ΔG (in kJ) for the following reaction at 1.0 atm for C2H6, 0.5 atm for O2, and 2.0 atm for CO2, and 25 oC: C2H6 (g) + O2 (g) ---> CO2 (g) + H2O (l) (unbalanced) ΔGfo C2H6 (g) = - 32.89 kJ/mol; ΔGfo CO2 (g) = - 394.4 kJ/mol; ΔGfo H2O (l) = - 237.13 kJ/mol
Answer:
Explanation:
Calculate ΔG (in kJ) for the following reaction at 1.0 atm for C2H6,
0.5 atm for O2, and
2.0 atm for CO2, and
25 oC:
C2H6 (g) + O2 (g) ---> CO2 (g) + H2O (l) (unbalanced)
ΔGfo C2H6 (g) = - 32.89 kJ/mol;
ΔGfo CO2 (g) = - 394.4 kJ/mol;
ΔGfo H2O (l) = - 237.13 kJ/mol
The balance equation of this reaction is
[tex]2C_2H_6 (g) + 7O_2 (g) ---> 4CO_2 (g) + 6H_2O (l)[/tex]
[tex]\Delta G_{rxn}=\sum G^o_f(product)-\sum G^o_f(reactant)[/tex]
[tex]=4G^o_f(CO_2)+6G^o_f(H_2O)-7G^o_f(O_2)-2G^o_f(C_2H_6)\\\\[/tex]
[tex][4(-394.4)+6(-237.13)-7(0)-2(-32.89)]kJ/mol\\\\=-1577.6-1422.78+65.78\\\\=-3000.38+65.78\\\\=-2934.6kJ/mol[/tex]
uppose you are standardizing a sodium hydroxide solution with K H P (molar mass=204.2 g/mol) according to the equation K H P + N a O H ⟶ H 2 O + N a K P You prepare the standard solution from 0.294 g of K H P in 250.0 mL of water. You then require 7.42 mL of N a O H solution to complete the titration. What is the concentration of the N a O H solution?
Answer: The concentration of NaOH solution is 0.194 M
Explanation:
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Given mass of KHP = 0.294 g
Molar mass of KHP = 204.22 g/mol
Putting values in above equation, we get:
[tex]\text{Moles of KHP}=\frac{0.294g}{204.22g/mol}=0.00144mol[/tex]
The chemical reaction follows the equation:
[tex]KHC_8H_4O_4(aq.)+NaOH\rightarrow KNaC_8H_4O_4(aq.)+H_2O(l)[/tex]
By Stoichiometry of the reaction:
1 mole of KHP reacts with 1 mole of NaOH.
So, 0.00144 moles of KHP will react with = 0.0144 of KOH.
To calculate the molarity of NaOH, we use the equation:
[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}[/tex]
We are given:
Moles of KOH = 0.00144 moles
Volume of solution = 7.42ml = 0.00742L (Conversion factor: 1L = 1000 mL)
Putting values in above equation, we get:
[tex]Molarity=\frac{0.00144mol}{0.00742L}=0.194M[/tex]
Hence, the molarity of NaOH solution is 0.194 M
The concentration of the NaOH solution used in complete titration has been 0.194 M.
The reaction of KHP with NaOH has been the neutralization reaction that results in the formation of salt and water.
The concentration of KHP solution has been:
Molarity = [tex]\rm \dfrac{weight}{Molecular\;weight}\;\times\;\dfrac{1000}{Volume\;(ml)}[/tex]
Molarity of KHP = [tex]\rm \dfrac{0.294}{204.2}\;\times\;\dfrac{1000}{250}[/tex]
Molarity of KHP = 0.0057 M
The concentration of the KHP solution has been 0.0057 M.
For the neutralization reaction in complete titration:
Molarity of acid [tex]\times[/tex] Volume of acid = Molarity of base [tex]\times[/tex] Volume of base
Substituting the values from the question:
0.0057 M [tex]\times[/tex] 250 ml = Molarity of NaOH [tex]\times[/tex] 7.42 ml
1.439 = Molarity of NaOH [tex]\times[/tex] 7.42 ml
Molarity of NaOH = 0.194 M.
The concentration of the NaOH solution used in complete titration has been 0.194 M.
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Spell out the full name of the compound.
Explanation:
Step one look for the longest chain of carbon atoms
Longest chain is 7 C atoms
Step 2 look for double bonds or others functional groups
it is present in 3rd carbon
Therefore IUPAC name is 3-heptene
From point of stereochemistry it can also be written as trans-3-heptene as the hydrogens are placed in opposite side of the C=C bond.
Hope this helps...
The compound name is: trans 3-heptene
What is molecular compound?Molecular compounds are inorganic compounds that take the form of discrete molecules.
Looking at the given compound:
1. We need to look for the highest carbon chain, So in this compound the highest carbon chain is of 7 carbon atoms.
2. This compound also has a double bond in between that is present at the third carbon which can be detected by numbering the carbon in a order where the lowest number will come over a double bond.
3. Lastly, we can derive the name for this compound as hept-3-ene or 3-heptene.
4. Also, there is one more thing to notice here which is the position of two hydrogen that are present as substituents since they are placed opposite to each other thus we can name it as trans 3-heptene.
Thus, the compound name is: trans 3-heptene.
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In the first step of glycolysis, the given two reactions are coupled. reaction 1:reaction 2:glucose+Pi⟶glucose-6-phosphate+H2OATP+H2O⟶ADP+PiΔG=+13.8 kJ/molΔG=−30.5 kJ/mol Answer the four questions about the first step of glycolysis. Is reaction 1 spontaneous or nonspontaneous?
Answer: Reaction 1 is non spontaneous.
Explanation:
According to Gibb's equation:
[tex]\Delta G=\Delta H-T\Delta S[/tex]
[tex]\Delta G[/tex] = Gibbs free energy
[tex]\Delta H[/tex] = enthalpy change
[tex]\Delta S[/tex] = entropy change
T = temperature in Kelvin
When [tex]\Delta G[/tex] = +ve, reaction is non spontaneous
[tex]\Delta G[/tex]= -ve, reaction is spontaneous
[tex]\Delta G[/tex]= 0, reaction is in equilibrium
For the given reaction 1: [tex]glucose+Pi\rightarrow glucose-6-phosphate+H_2O[/tex] [tex]\Delta G=+13.8kJ/mol[/tex]
As for the reaction 1 , the value of Gibbs free energy is positive and thus the reaction 1 is non spontaneous.
QUESTION 11
Which of the following compounds has the highest boiling poid?
O CH3CH2CH2COOH
O CH3OCH2CH2CH3
O CH3CH2CH2OH
O CH3CH2CH2CHO
Answer:
CH3CH2CH2COOH
Explanation:
Both carboxylic acids and alcohols posses hydrogen bonding. The difference between the two lies in the strength of the hydrogen bonding and the structure of the molecules.
Alcohols predominantly form linear hydrogen bonds in which the dipole of the -OH group of one molecule interacts with that of another molecule. This gives a linear arrangement of hydrogen bonded intermolecular interactions which significantly impacts the boiling point of alcohols.
However, the carboxylic acids posses the carbonyl (C=O) which is more polar and interacts more effectively with the -OH bond to form dimmer species. These dimmers have a much higher boiling point than the corresponding alcohols due to stronger hydrogen bonds. Hence CH3CH2CH2COOH has a greater boiling point than CH3CH2CH2OH.
The other compounds in the options do not posses hydrogen bonds hence they will have much lower boiling points.
3. In the above molecules, generally the octet rule can not be followed for every atom. When there are too many electrons or two few electrons and the atoms cannot or will not form multiple bonds, which atom in the structure does not receive a complete or has an expanded octet? Explain why only one atom in the structure is affected in these situations.
Answer:
The octet rule is possible in those atoms which has high number of electrons in their shells.
Explanation:
The octet rule is a type of rule in which the atom has 8 electrons in its outermost shell or valance shell. This rule is not possible for hydrogen and helium because there are very less number of electrons and we know that octet rule needed more number of electrons. Only one atom may be hydrogen or helium is affected in the structure is affected in these situations due to presence of less number of electrons in shells.
Given the following Fischer projection: Fischer projection for an entantiomer of 2-bromo-2,3-dihydroxypropanal with the bromine oriented horizontally to the left and the hydroxide group oriented horizontally to the right. draw the perspective formula of the molecule. Be sure to correctly indicate stereochemistry in your answer.
Answer:
Explanation:
Stereoisomers are two or more atoms that have the same bonding order of atoms but there is a difference spatial arrangement of the atoms in space.
A plane of symmetry divides a molecule into two equal halves.
A chiral stereoisomer are not superimposed on a mirror image , Hence they do not posses a plane of symmetry.
As a result to that. these non-superimposable mirror images are said to be Enantiomers.
However, a Fischer Projection emanates from a two - dimensional figure which is used for presenting a three - dimensional organic molecules.
From the given question;
Fischer projection for an enantiomer of 2-bromo-2,3-dihydroxypropanal with the bromine oriented horizontally to the left and the hydroxide group oriented horizontally to the right.
we can sketch the way the enantiomer of 2-bromo-2,3-dihydroxypropanal can be seen like the one shown below:
CH₂OH
|
|
|
Br -------------|----------------OH
|
|
|
CHO
The objective of this question is to drawn the perspective formula of the molecule.
So , from the attached file below; we can see the perspective formula of the molecule in a well structured 3-D format.
Rank the following transitions in a hydrogen atom in order of increasing wavelength of electromagnetic radiation that could produce them. Answer this question without doing any calculations. Explain the order.
n=2 to n=4
n=6 to n=8
n=10 to n=12
n=14 to n=16
Answer:
n=2 to n=4 < n=6 to n=8 < n=10 to n=12 < n=14 to n=16
Explanation:
According to Neils Bohr, electrons in an atom are found in specified energy levels. Transitions are possible from one energy level to another when the electron receives sufficient energy usually in the form of a photon of electromagnetic radiation of appropriate frequency and wavelength. The energy of this photon corresponds to the energy difference between the two energy levels. Thus the higher the energy difference between energy levels, the greater the energy of the photon required to cause the transition and the shorter the wavelength of the photon.
High energy photons have a very short wavelength. It should be noted that as n increases, the energy of successive energy levels decreases and transitions between them now occurs at longer wavelengths. Hence, the highest energy and shortest wavelength of photons are required for transition involving lower values of n because such electrons are closer to the nucleus and are more tightly bound to it than electrons found at a greater distance from the nucleus.
Hence transition involving electrons at higher energy levels occur at a longer wavelength compared to transition involving electrons closer to the nucleus. This is the basis for the arrangement of wavelengths required to effect the various electronic transitions shown in the answer.
g If a sample of 50 mL of ethyl benzene (bp = 136 C) was contaminated with 10 mL of ethyl acetate (bp = 77 C) what effect would this have on the boiling point measurement?
Answer:
melting point will be higher than that of pure ethyl acetate
Explanation:
Perform the conversions between energy units.
861 kJ=
J
3495 kcal=
kJ
7.84×106
Answer:
861 kJ = 861000 J,
3495 kcal = 14623.08 kJ
Explanation:
As I mentioned before, the last bit " 7.84 × 106 " just threw me off track, so I am simply going to assume that that does not appear in your question.
_______________________________________________________
Now we have 861 kilojoules, and have to convert it into joules for this first bit. Kilo being equal to 1000, to convert to joules you would have to multiply 861 by 1000, = 861000 Joules.
This second bit here asks us to convert 3495 kilocalorie to kilojoules. The difference between the two is that one is about 4.18 times greater than the other, so 3495 kilocalorie = 3495 * 4.18 = 14623.08 kilojoules.
Hope that helps!
Consider each of the following molecules in turn: (a) dimethyl ether, (CH3)2O; (b) trimethylamine, (CH3)3N; (c) trimethylboron, (CH3)3B; and (d) carbon dioxide (CO2). Describe the hybridization state of the central atom (i.e., O, N, B, or C) of each molecule, tell what bond angles you would expect at the central atom, and state whether the molecule would have a dipole moment.
Answer:
Consider each of the following molecules in turn: (a) dimethyl ether, (CH3)2O; (b) trimethylamine, (CH3)3N; (c) trimethylboron, (CH3)3B; and (d) carbon dioxide (CO2). Describe the hybridization state of the central atom (i.e., O, N, B, or C) of each molecule, tell what bond angles you would expect at the central atom, and state whether the molecule would have a dipole moment.
What force is needed to accelerate a truck with mass 2,000 kg at a rate of 5.0
m/s22
O A. 1,000 N
B. 20,000 N
C. 2,000 N
O D, 10,000 14
Answer:
D
Explanation:
[tex]F=ma \\\\F=2000\cdot 5=10,000N[/tex]
Hope this helps!
The first solution will be an unbuffered sucrose solution. Calculate the amount of 0.1 M sucrose stock solution and the amount of dH2O needed to prepare 100 mL of unbuffered 20 mM sucrose.
Answer:
20mL of the stock solution and dilute to 100mL
Explanation:
20mM = 0.020M is the concentration of the diluted solution. As you want to prepare this solution from a 0.1M solution, dilution factor is:
0.1M / 0.020M = 5
That means you need to dilute the stock solution 5 times to obtain the 20mM sucrose solution.
As you want to prepare 100mL, you need to add:
100mL / 5 =
20mL of the stock solution and dilute to 100mLWhich metal will spontaneously react with Zn2+
(aq),
but will not spontaneously react with Mg2+
(aq)
according to the activity series
The options of the question is not given so the options are;
(1) Mn(s)
(2) Cu(s)
(3) Ni(s)
(4) Ba(s)
Answer: Mn(s)
Explanation:
The spontaneous reaction depends on the Eo value. The positive Eo value are spontaneous and the negative Eo values are not spontaneous.
so, here the Eo values are:
Eo Zn2+/Zn = -0.763v
Eo Mg2+/Mg = 2.37v
Eo Mn2+/Mn = -1.18v
Therefore, Eo cell (with Zn as one of the half-cell) = Eo Zn2+/Zn - Eo Mn2+/Mn
= -0.763 - (-1.18)
= 0.417v
Whereas, Eo cell (with Mg as one of the half-cell) = Eo Mg2+/Zn - Eo Mn2+/Mn
= -2.37 - (-1.18) = -1.19v
Thus, Mn(s) metal will spontaneously react because it has a positive Eo value and Zn2+(aq), but will not spontaneously react with Mg2+(aq) because it has negative Eo value.
Pre-Lab Study Questions / 9
1. Where are the valence electrons in an atom?
valen
2. How are positive and negative ions fomed?
3. Why are electrons shared in molecular compounds?
Answer:
See detailed answer with explanation below.
Explanation:
Valence electrons are electrons found on the outermost shell of an atom. They are the electrons in an atom that participate in chemical combination. Recall that the outermost shell of an atom is also referred to as its valence shell. Let us consider an example; if we look at the atom, sodium-11, its electronic configuration is 2,8,1. The last one electron is the valence electron of sodium which is found in its outermost or valence shell.
Positive ions are formed when electrons are lost from the valence shell of an atom. For instance, if the outermost electron in sodium is lost, we now form the sodium ion Na^+ which is a positive ion. Positive ions possess less number of electrons compared to their corresponding atoms.
Negative ions are formed when one or more electrons is added to the valence shell of an atom. A negative ion possesses more electrons than its corresponding atom. For example, chlorine(Cl) contains 17 electrons but the chloride ion (Cl^-) contains 18 electrons.
In molecular compounds, a bond is formed when two electrons are shared between the bonding atoms. Each bonding atom may contribute one of the shared electrons (ordinary covalent bond) or one of the bonding atoms may provide the both shared electrons (coordinate covalent bond). The shared pair may be located at an equidistant position to the nucleus of both atoms. Similarly, the electron may be drawn closer to the nucleus of one atom than the other (polar covalent bond) depending on the electro negativity of the two bonding atoms.
The electrons are shared in order to complete the octet of each atom by so doing, the both bonding atoms now obey the octet rule. For example, two chlorine atoms may come together to form a covalent bond in which each chlorine atom has an octet of electrons on its outermost shell.
How many elements make up most of the ocean?
Answer:
Hydrogen and oxygen
Explanation:
Answer:
eight
Explanation:
the elements of course are the following
hydrogen
oxygen
calcium
sodium
sulfur
magnesium
chlorine
potassium
i hope this helps you
What is the law of conservation and what happens when two substances at different temperatures come into contact.
Answer:
- Both energy and matter cannot be neither created nor destroyed.
- An equilibrium temperature will be reached.
Explanation:
Hello,
In this case, the law of conservation is applied to both matter and energy, and it states that both energy and matter cannot be neither created nor destroyed. Specifically, in chemical reactions, it states that in closed systems, the mass of the reactants equals the mass of the products even when the number of moles change. Moreover, for energy, if two substances at different temperatures come into contact, the hot one will cool down and the cold one will heat up until an equilibrium temperature so the energy lost by the hot one is gained by the cold one, which accounts for the transformation of energy.
Best regards.
Nitrosyl bromide, NOBr, is formed from NO and Br2.
2 NO(g) + Br2(g) 2 NOBr(g)
Experiments show the reaction is second order in NO and first order in Br2.
How does the reaction rate change if the concentration of Br2 is changed from 0.0022 mol/L to 0.0066 mol/L?
a) the rate will double
b) the rate will remain unchanged
c) the rate will triple
Answer:
C ) The rate will triple
For each of the following pairs of elements
(1C and N2) (1Ar and Br2)
pick the atom with
a. more favorable (exothermic) electron affinity.
b. higher ionization energy.
c. larger size.
How do you even go about do this?
Explanation:
Electron affinity is defined as the energy released by the addition of an electron to any gaseous atom. Electron affinity of an atom depends on the electronic configuration.
a).The carbon has vacant p-orbital and nitrogen has half-filled configuration which is more stable. Therefore, one electron can be easily added to carbon whereas nitrogen having more stable configuration releases more amount of energy on adding one electron. Therefore, nitrogen has more electron affinity than carbon.
The bromine has vacant p-orbital whereas argon has filled orbital which is most stable. Therefore, one electron can be easily added to bromine whereas argon having more stable configuration releases more amount of energy on adding one electron.Therefore, argon has more electron affinity than bromine.
Answer:
1. a. C; b. N; c. C; 2. a. Br; b. Ar; c. Br
Explanation:
Use your Periodic Table and follow the trends in atomic properties (Fig. 1).
Electron affinity increases from left to right and from bottom to top.
The elements with the most exothermic EA are at the upper right corner
Exceptions are the noble gases (group 18) and the pnictogens (group 18).
The elements of Group 18 have a complete octet and have no tendency to accept electrons.
The elements of Group 15 have half-filled p subshells. They are more stable than the elements immediately preceding them, so they are less exothermic when adding an electron.
Ionization energy increases from left to right and from bottom to top.
The atoms with the highest IE are at the upper right corner.
Atomic size increases from right to left and from bottom to top.
The largest atoms are on the lower-left corner.
1. C vs N
(a) EA: C. N is a Group 15 element
(b) IE: N. N is further to the right.
(c) Size: C. C is further to the left.
2. Ar vs Br
(a) EA: Br. Ar is a noble gas.
(b) IE: Ar. Ar is further to the right.
(c) Size: Br. Br is nearer to the bottom.
(03.01 LC
Which of the following is not present in an atom? (1 point)
Answer:
Protons, Neutrons, and Electrons are all in atoms so the one not present would be the Element since Elements are made of atoms.
Explanation:
Consider the heating curve for water. A graph of the heating curve for water has time in minutes on the horizontal axis and Temperature in degrees Celsius on the vertical axis. A line runs through the following points: 0 minutes, negative 20 degrees; 0.5 minutes, 0 degrees; 2 minutes, 0 degrees; 4 minutes, 100 degrees; 8 minutes, 100 degrees; 9.5 minutes, 160 degrees. At what temperature does the solid start melting? –20°C 0°C 20°C 80°C
Answer:
0°C.
Explanation:
Hello,
In this case, given the heating curve of water on the attached document, we can notice that at 0 °C the solid starts melting, which means that the melting point is reached. Melting point is known as a physical change whereby a solid changes to liquid by the addition of heat as it allows the molecules to separate to each other.
Best regards.
Answer:
0 degrees celcius
Explanation:
I took the test
AMMONIUM CARBONATE
5. How many grams of nitrogen (N) are in a mass of ammonium carbonate that contains
1.23x10^23 carbon atoms?
Answer:
Zero
Explanation:
Hello,
The question require us to calculate the mass of nitrogen present in aluminium carbonate.
This can easily be calculated using Avogadro's number as a constant with some minor calculations but however in this case, we can't because there's no single atom of nitrogen present in aluminium carbonate hence we can't calculate the mass of nitrogen present in it.
Chemical formula of aluminium carbonate = Al₂(CO₃)₃.
From the above chemical formula, we can see that there's no single atom of nitrogen present in the formula hence the mass of nitrogen present in aluminium carbonate that contains 1.23×10²³ carbon atoms is zero.
Because cylinder with a volume of 3.00dm^3 contains 8.00 moles of oxygen gas at a temperature of 50.0 K. What is the pressure inside the cylinder? ( R=8.31)
Answer:
Option A. 1110 KPa.
Explanation:
The following data were obtained from the question:
Volume (V) = 3 dm³
Number of mole (n) = 8 moles
Temperature (T) = 50K
Gas constant (R) = 8.31 KPa.dm³/Kmol
Pressure (P) =..?
Pressure inside the cylinder can be obtained by using the ideal gas equation as follow:
PV =nRT
P x 3 = 8 x 8.31 x 50
Divide both side by 3
P= (8 x 8.31 x 50) /3
P = 1108 ≈ 1110 KPa
Therefore, the pressure inside the cylinder is 1110 KPa
The first three excited states of the nucleus Au-199 (gold) are at 0.075 Mev, 0.320 Mev and 0.475 MeV. If all transitions between theses states and the ground state occurred, what energy/wavelength gamma rays would be observed?
Answer and Explanation:
The computation of the energy or wavelength gamma rays observed is shown below:
Since the energy of gamma rays is higher than 0.10 MeV.
Now We have to calculate transitions in between the given levels of energy that correspond to this energy.
As per the given question, we have the following information
Ground state = E where E < 0.075 MeV
For Level 1 = 0.075 MeV
For Level 2 = 0.320 MeV
For Level 3 = 0.475 MeV
Now we have to take the below transitions:
1. [tex]3 \rightarrow 2[/tex]
Difference of energy is
= 0.475 - 0.320
= 0.155 MeV
This represents a gamma radiation
2. [tex]3 \rightarrow 1[/tex]
Difference of energy is
= 0.475 - 0.075
= 0.4 MeV
This represents a gamma radiation
3. [tex]3 \rightarrow ground[/tex]
Difference of energy is
= 0.475 - E > 0.155 MeV
This represents a gamma radiation
4. [tex]2 \rightarrow 1[/tex]
Difference of energy is
= 0.320 - 0.075
= 0.245 MeV
This represents a gamma radiation
5. [tex]2 \rightarrow ground[/tex]
Difference of energy is
= 0.320 - E > 0.245 MeV
This represents a gamma radiation
6. [tex]1 \rightarrow Ground[/tex]
Difference of energy is
= 0.075 - E < 0.10 MeV
This represents not a gamma radiation
We can see that there are 5 transitions that contain gamma rays
Q#1 Give a combination of four quantum numbers that could be assigned to an electron occupying a 5p orbital.
Express your answers using one significant figures. Enter your answers separated by commas.
The answer n, l, ml, ms = 5,1,-1,0,or1,-1/2or+1/2
mastring chemistry says
"Incorrect; Try Again; 6 attempts remaining; no points deducted
Your answer does not have the correct number of comma-separated terms."
the same for q#2
Do the same for an electron occupying a 6d orbital.
Express your answers using one significant figures. Enter your answers separated by commas.
the answer n, l, ml, ms =6,0,1,2,-2,-1,0,+1,+2,+1/2or-1/2
Answer:
For an electron in 5p orbital
5,1,-1,+1/2
For an electron in 6d orbital
6,2,-2,+1/2
Explanation:
The term quantum numbers refers to a set of values that can be used to determine the region in space where it is likely to find an electron. This region in space where there is a high probability of finding an electron is known as an atomic orbital. An atomic orbital is actually a wave function according to the Schrödinger wave equation.
There are four quantum numbers used in describing an atomic orbital: the principal quantum number (n), the orbital angular momentum quantum number also called azimuthal or subsidiary quantum number (l), the magnetic quantum number (ml), and the electron spin quantum number (ms).
For a 5p orbital;
n= 5, l= 1, ml= -1,0,1 ms= +1/2 or -1/2
For 6d orbital;
n= 6, l= 2, ml= -2,-1,0,1,2, ms= +1/2 or -1/2
Since we are requested to use a four quantum number description that can be assigned to an electron in these levels;
For an electron in 5p orbital
5,1,-1,+1/2
For an electron in 6d orbital
6,2,-2,+1/2
Use the link Standard Reduction Potentials. Write net equations for the spontaneous redox reactions that occur during the following or none (all lower case) if there is no extensive reaction. Use the lowest possible coefficients. A) Iron metal is dipped into a Ni2+ solution.B) Copper metal is added to hydrochloric acid.C) A silver wire is added to nitric acid (HNO3).D) Magnesium metal is added to waterE) Chromium metal is added to a solution of Mg2+
Answer:
a) Fe(s) + Ni^2+(aq) ----> Fe^2+(aq) + Ni(s)
b) no reaction
c) no reaction
d) 2Mg(s) + 2H2O(l)-----> 2Mg^2+(aq) + O2(g) +4H^+(aq)
e) no reaction
Explanation:
It is important to say here that the ability of a particular chemical specie to displace another chemical specie is dependent on the relative standard reduction potentials of the species involved.
All the reactions stated above are redox reactions. Let us take reaction E as an example. Mg^2+ has a reduction potential of -2.37 V while Cr^3+ has a reduction potential of -0.74V. Since the reduction potential of magnesium is more negative than that of chromium, there is no reaction when a piece of chromium metal is dipped into a solution of Mg^2+.
Similarly, though metals displace hydrogen gas from dilute acids, metals that are less than hydrogen in the reactivity series cannot do that. This explains why there is no reaction when copper and silver are dipped into dilute acid solutions.
Reaction occurs when iron is dipped into a nickel solution because the reduction potential of Fe^2+ is far more negative than that of Ni^2+.