Answer:
25
Explanation:
bec
How many significant figures are in a measurement of 28.050 km?
Answer:
has 5, ans 3 decimals.
thats as simple as i can put it.
True or False
Helium belongs to Noble Metals
Answer:
This answer is "True"
A central idea in modern quantum mechanics is:
(4 Points)
A wave character exhibited by all particles.
The acceleration of charged particles moving around a nucleus.
The opportunity to locate the position of an electron exactaly.
The continuous range of energies that electrons can have.
Answer:
A wave character exhibited by all particles
Explanation:
The central idea in quantum mechanics is the paradox of wave-particle duality. In quantum mechanics, all particles are believed to also exhibit wavelike characters.
The electron is assumed to behave as a wave hence its position can not be precisely determined according the Heisenberg's uncertainty principle.
These are the underlying postulates that informed Erwin Schrödinger's wave mechanical model of the atom.
Hence, the basic postulate of quantum mechanics is that a wave character is exhibited by all particles.
I need help please ASAP
Answer:
the name for NO is nitrogen monoxide
How many molecules are in 0.5 grams of ammonia, NH3?
Answer:
I dont no ma men
Explanation:
Sorry cause a dont no
You are given a 250 ml sample of HCI and asked to find out what its concentration is. You have a 0 118 M Ca(OH)2 solution and it takes 13.7 ml to
neutralize the acid sample. What is the concentration of the HCI? Show explanation Please help this is urgent
Answer:
The concentration of the acid, HCl is 0.013 M
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2HCl + Ca(OH)₂ —> CaCl₂ + 2H₂O
From the balanced equation above,
The mole ratio of the acid, HCl (nₐ) = 2
The mole ratio of base, Ca(OH)₂ (n₆) = 1
Finally, we shall determine the molarity of the HCl. This can be obtained as follow:
Volume of acid, HCl (Vₐ) = 250 mL
Molarity of base, Ca(OH)₂ (M₆) = 0.118 M
Volume of base, Ca(OH)₂ (V₆) = 13.7 mL
Molarity of acid, HCl (Mₐ) =?
MₐVₐ / M₆V₆ = nₐ/n₆
Mₐ × 250 / 0.118 × 13.7 = 2/1
Mₐ × 250 / 1.6166 = 2
Cross multiply
Mₐ × 250 = 1.6166 × 2
Mₐ × 250 = 3.2332
Divide both side by side 250
Mₐ = 3.2332 / 250
Mₐ = 0.013 M
Thus, the concentration of the acid, HCl is 0.013 M
We can determine the potential of a single electrode by:____________.
a. attaching it to a voltmeter
b. determining the electronegativity of its component elements
c. measuring its mass
d. none of the above
Answer:
d. none of the above
Explanation:
An electrochemical cell consists of two half-cells, with each cell containing an electrode.
The potential of a single electrode in a half-cell is called the Single electrode potential.
The emf of a cell that consists of two half-cells can be determined by connecting them to a voltmeter.
However, there is no way of measuring the emf of a single half-cell directly.
The only way to determine the emf of a single electrode is to combine it with a standard hydrogen electrode (SHE) and measure it with a voltmeter.
Therefore, the correct option is D "none of the above"
An electrochemical cell consists of two half-cells, with each cell containing an electrode.
What is an electrochemical cell?
An electrochemical cell is a device that can generate electrical energy from the chemical reactions occurring in it, or use the electrical energy supplied to it to facilitate chemical reactions in it.
The potential of a single electrode in a half-cell is called the Single electrode potential.The emf of a cell that consists of two half-cells can be determined by connecting them to a voltmeter.
The only way to determine the emf of a single electrode is to combine it with a standard hydrogen electrode (SHE) and measure it with a voltmeter.
Hence the correct option is D.
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Share the same molecular formula but have different connectivity of atoms and different physical properties.
Answer:
Constitutional Isomers
Explanation:
Constitutional isomers can be regarded as structural isomers ,these are compounds that have the same molecular formula with different structural formulas. Example is Butane and isobutane; both compound posses the same molecular formula(C4H10) with different structural formulas. compounds of Constitutional isomers are differ in term of connectivity, which
is the way the constituent atoms are been connected to another. It should be noted that Constitutional Isomers Share the same molecular formula but have different connectivity of atoms and different physical properties.
It is important for scientists to know how much energy is given off or absorbed in a chemical reaction. Which options below would indicate an exothermic reaction?
delta H = –
delta H = +
Energy is considered a reactant in the reaction: A + B + energy ---> C + D
Energy is considered a product in the reaction: A + B ---> C + D + energy
Energy is released in the reaction.
Energy is absorbed in the reaction.
For exothermic reactions, ΔH is always negative, energy is considered a product, and energy is released in the reaction.
An exothermic reaction is one in which energy, usually in the form of heat, is released to the environment from the reaction. In other words, the final temperature of an exothermic reaction would always be more than the initial temperature.
This also means that heat energy is a product of exothermic reactions and this heat is released to the environment from the reaction.
More on exothermic reactions can be found here: https://brainly.com/question/10373907?referrer=searchResults
Answer:
a, d, and e is correct on edge of the nuity
Explanation:
have a good day
g Select the statement that best answers the following question What effect does the cation of an ionic compound have on the appearance of the solution? The cation affects the intensity of the color more than the color of the solution. The cation affects the color of the solution more than the intensity of the color. The cation does not affect the color or color intensity of the solution. The cation only affects the intensity of the color in a solution.
Answer:
The cation affects the intensity of the color more than the color of the solution.
Explanation:
According to Beer Lambert law, the intensity of the colour of the solution depends on the concentration of the specie responsible for the colour in the solution.
Let us recall that transition metal compounds are coloured in solution due to electronic transitions.
Therefore, the cation affects the intensity of the color more than the color of the solution.
I NEED THIS NOW AND NO LINKS OR ILL REPORT
Which material creates the most waste and pollutants when creating one
ton of bottles? *
aluminum
glass
plastic
Answer:
plastic
........................
When heated, magnesium combines readily with excess oxygen in the air to produce magnesium oxide, as shown in the following unbalanced equation.
Mg (s) + O2 (g) → MgO (s) + heat
What two types of reactions could this chemical equation be classified as?
Answer: The given chemical reaction can be classified as synthesis and exothermic.
Explanation:
A synthesis reaction is defined as the reaction where two small chemical species combine in their elemental state to form a single large chemical species.
Exothermic reactions are defined as the reactions in which heat is released by the reaction. The heat is written on the product side of the reaction.
For the given chemical reaction:
[tex]Mg(s)+O_2(g)\rightarrow MgO(s)+\text{heat}[/tex]
The above chemical reaction is a type of synthesis and exothermic as two substances in their elemental state are combining. Also, heat is getting released in the reaction.
Hence, the given chemical reaction can be classified as synthesis and exothermic.
The sloth is able to camouflage by moving really slowly and
A. changing colors
B. hanging upside down
D. having fur that is a similar color to tree barks with algae growing on it
Answer:
D. having fur that is a similar color to tree barks with algae growing on it
Explanation:
Choice A doesnt make sense because sloths do not change colors, and hanging upside down would not protect you from prey or blend in. D matches the description of a sloth.
Answer:
Having fur that is a similar color to tree barks with algae growing on it.
Explanation:
g Using Newman projections, draw the most stable conformation for each of the following compounds. (a) 3-methyl pentane, viewed along the C2-C3 bond (b) 3,3-dimethyl hexane, viewed along the C3-C4 bond
Answer:
Using Newman projections, draw the most stable conformation for each of the following compounds.
(a) 3-methyl pentane, viewed along with the C2-C3 bond.
(b) 3,3-dimethyl hexane, viewed along with the C3-C4 bond.
Explanation:
(a) The structure of 3-methyl pentane is shown below:
In Newman projection, the most stable conformation is staggard conformation.
In staggard conformation, the torsional strain is very less compared to eclipsed conformation.
(b)3,3-dimethyl hexane, viewed along with the C3-C4 bond.
what's the ph of 0.0000067 m hcl solution
Answer:
[tex]pH = - log[H {}^{ + } ] \\ = - log(0.0000067) \\ pH = 5.17[/tex]
(iii) Give areason why the nitrogen gas obtained is not pure
Answer:
jhhhhhhhhh
Explanation:
dffffffffffffg
To determine the freezing point depression of a LiCl solution, Toni adds 0.411 g of LiCl to the sample test tube along with 19.7 mL of distilled water. Determine the molal concentration (m) of the resulting solution. MWLiCl
Answer:
LiCl = 0.492 m
Explanation:
Molal concentration is the one that indicates the moles of solute that are contained in 1kg of solvent.
Our solute is lithium chloride, LiCl.
Our solvent is distilled water.
We do not have the mass of water, but we know the volume, so we should apply density to determine mass.
Density = mass / volume
Density . volume = mass
1 g/mL . 19.7 mL = 19.7 g
We convert g to kg → 19.7 g . 1 kg / 1000g = 0.0197 kg
Let's determine the moles of LiCl
0.411 g . 1 mol / 42.394 g = 9.69×10⁻³ moles
Molal concentration (m) = 9.69×10⁻³ mol / 0.0197 kg → 0.492 m
The molal concentration of the resulting solution is 0.492 m. The concentration number of moles of solute in one kg of solvent.
What is Molal concentration?It is the measure of the concentration number of moles of solute in one kg of solvent.
To calculate the molal concentration first calculated the mass of [tex]\bold {LiCl}[/tex],
[tex]\rm \ mass = density \times volume[/tex]
Put the values,
m = 1 g/mL x 19.7 mL
m = 19.7 g or
m = 0.0197 kg
Calculate the moles of LiCl:
[tex]n =\rm \dfrac { 0.411 \ g \times 1 mol }{ 42.394 \ g }\\\\n = 9.69\times 10^{-3} \ moles[/tex]
So, now the molal concentration,
[tex]m = \rm \dfrac { 9.69\times 10^{-3}\ mol} {0.0197 \ kg} \\\\m = 0.492[/tex]
Therefore, the molal concentration of the resulting solution is 0.492 m.
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A substance with two oxygen atoms is combined with a substance with one oxygen atom to form one product. What is true of the product?
There will be no oxygen in the product. Some of the oxygen will evaporate into the air.
If 0.3250 L of 0.125 M NaOH base were used in a titration, what were the moles of base?
Answer:
Explanation:You can download the ly/3fcEdSxans[tex]^{}[/tex]wer here. Link below!
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According to molar concentration, there are 0.0406 moles of base used in the titration.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.Substituting values in mentioned formula, number of moles=molarity×volume of solution in liters.
∴number of moles=0.125×0.3250=0.0406 moles
Thus, 0.0406 moles are used in the titration.
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Scientist A produces 83.67 g KMnO4 while Scientist B produces 81.35 g KMnO4.
What is the percent yield for Scientist A?
What is the percent yield for Scientist B?
You must show all work to receive full credit.
The equation for the production of potassium permanganate is as follows:
2 MnO2 + 2 KOH + O2 → 2 KMnO4 + H2
Answer:
[tex]Y_A=92.1\%\\\\Y_B=89.6\%[/tex]
Explanation:
Hello there!
In this case, according to the given chemical equation for the reaction for the production of potassium permanganate, we can see a 2:2 mole ratio of this product to the starting manganese (II) oxide, which means, we can calculate the theoretical yield of the former via stoichiometry:
[tex]m_{KMnO_4}=50.0gMnO_2*\frac{1molMnO_2}{86.94gMnO_2}*\frac{2molKMnO_4}{2molMnO_2} *\frac{158.034gKMnO_4}{1molKMnO_4} \\\\m_{KMnO_4}=90.9gKMnO_4[/tex]
Now, we are able to compute the percent yields, by using the actual yield each scientist got:
[tex]Y_A=\frac{83.67g}{90.9g} *100\%=92.1\%\\\\Y_B=\frac{81.35g}{90.9g} *100\%=89.6\%[/tex]
Regards!
Calculate the number of milliliters of 0.587 M NaOH required to precipitate all of the Fe3 ions in 197 mL of 0.654 M FeCl3 solution as Fe(OH)3. The equation for the reaction is: FeCl3(aq) 3NaOH(aq) Fe(OH)3(s) 3NaCl(aq)
Answer: The number of milliliters of 654 mL for 0.587 M NaOH required to precipitate all of the [tex]Fe^{3+}[/tex] ions in 197 mL of 0.654 M [tex]FeCl_{3}[/tex] solution as [tex]Fe(OH)_{3}[/tex].
Explanation:
The reaction equation is as follows.
[tex]FeCl_{3}(aq) + 3NaOH(aq) \rightarrow Fe(OH)_{3}(s) + 3NaCl(aq)[/tex]
Therefore, moles of [tex]Fe(OH)_{3}[/tex] are calculated as follows.
Moles = Molarity of [tex]Fe(OH)_{3}[/tex] [tex]\times[/tex] Volume (in L)
= 0.654 M [tex]\times[/tex] 0.197 L
= 0.128 mol
Now, according to the given balanced equation 1 mole of [tex]FeCl_{3}(aq)[/tex] reacts with 3 moles of NaOH(aq). Hence, moles of [tex]Fe(OH)_{3}[/tex] reacted are calculated as follows.
3 [tex]\times[/tex] 0.128 mol = 0.384 moles of NaOH
As moles of NaOH present are as follows.
Moles of NaOH = Molarity of NaOH [tex]\times[/tex] Volume (in L)
0.384 mol = 0.587 M [tex]\times[/tex] Volume (in L)
Volume (in L) = 0.654 L (1 L = 1000 mL) = 654 mL
Thus, we can conclude that the number of milliliters of 654 mL for 0.587 M NaOH required to precipitate all of the [tex]Fe^{3+}[/tex] ions in 197 mL of 0.654 M [tex]FeCl_{3}[/tex] solution as [tex]Fe(OH)_{3}[/tex].
Element compound2. Select all the compounds from the following elements
HE
Fe2O3
O2
P4
C2H4O2
Answer: [tex]Fe_2O_3[/tex] and [tex]C_2H_4O_2[/tex] are the compounds.
Explanation:
A chemical compound is defined as a chemical substance that is formed by the combination of two or more atoms of different elements which cannot be separated by any physical means but when chemically treated, they decompose into their parent elements.
For example, water is made up of hydrogen and oxygen. This compound is a liquid and its individual components are gases. When water is decomposed, it forms hydrogen and oxygen gas.
For the given options:
He(Helium) is an element formed by the combination of only type of atoms.
[tex]O_2[/tex] and [tex]P_4[/tex] are molecules of same element.
[tex]Fe_2O_3[/tex] is a compound fomed by the combination of iron and oxygen atoms.
[tex]C_2H_4O_2[/tex] is a compound fomed by the combination of carbon, hydrogen, and oxygen atoms.
Hence, [tex]Fe_2O_3[/tex] and [tex]C_2H_4O_2[/tex] are the compounds.
How do scientists test their ideas
Which of the following is not a polymer
A. Glucose.
B. Starch.
C. Cellulose.
D. DNA.
Answer:
A. Glucose
Explanation:
Glucose is a monomer and not a polymer. So, option (A) is not a polymer.
Glucose is not a polymer because it is a kind of molecule while Starch , cellulose and DNA are polymers.
The correct answer is option A. Glucose.
What is the purpose of the scientific method
A rock was weighed on a balance and found to have a mass of 34.56 grams. It was placed into water that was in a graduated cylinder. Before the rock was dropped into the water the water level was 22.7 mL. The addition of the solid object caused the water level to rise to 28.1 mL. What is the density of the rock?
Answer:
5 and the rest are all set to the same date on your list as the other one to get you a list on for a your special first year week and with a special holiday party holiday
Explanation:
Sorry desperate for points
What is the pH of 0.6 M NaOH?
Answer:
pOH = - log[OH-]
[OH-] = 0.6M
[tex]pOH \: = - log(0.6) \\ = 0.2218487496 \\ pH \: + pOH \: = 14 \\ pH \: + 0.221848749 = 14 \\ pH = 14 - 0.221848749 \\ = 13.77815125 \\ 13.8[/tex]
An elephant walks north from a watering hole for 1 mile. The elephant
encounters a hill and turns east. The elephant continues to walk east until it
reaches a tree. It stays near the tree for 1 hour before continuing on to a
grassy field. Which point of reference should be used to describe the
elephant's motion?
A. The grassy area
B. The hill
STA
Tel
C. The tree
D. The watering hole
Answer:
i think its c because thats when the direction changes and you dont know where he went.
Explanation:
163 mL of 2.75 mol/L aluminum sulfate is to have all aluminum ions removed by adding a 3.65 mol/L sodium sulfide solution.
Al2(SO4)3(aq) + 3 Na2S(aq) → Al2S3(s) + 3 Na2SO4(aq)
What is the minimum volume of sodium sulfide that must be added to completely remove all the aluminum ions? What mass of aluminum sulfide will form?
Answer:
[tex]V_{Na_2S}=368mL[/tex]
[tex]m_{Al_2S_3}=67.3gAl_2S_3[/tex]
Explanation:
Hello there!
In this case, according to the given information, it is possible to realize that the only way for us to calculate the required volume of sodium sulfide, is by calculating the moles of this substance consumed 163 mL of 2.75 mol/L aluminum sulfate by using the definition of molar concentration and the 1:3 mole ratio between these two:
[tex]n_{Na_2S}=0.163L*2.75\frac{molAl_2(SO_4)_3}{L}*\frac{3molNa_2S}{1molAl_2(SO_4)_3} =1.34molNa_2S[/tex]
Now, we divide these moles by the molar concentration of sodium sulfide to obtain the required volume:
[tex]V_{Na_2S}=\frac{1.34molNa_2S}{3.65mol/L} =0.368L=368mL[/tex]
For the last part, we now use the 1:1 mole ratio of aluminum sulfate to aluminum sulfide and the molar mass of the latter (150.158 g/mol) in order to calculate the required mass:
[tex]m_{Al_2S_3}=0.163L*2.75\frac{molAl_2(SO_4)_3}{L}*\frac{1molAl_2S_3}{1molAl_2(SO_4)_3} *\frac{150.158gAl_2S_3}{1molAl_2S_3} \\\\m_{Al_2S_3}=67.3gAl_2S_3[/tex]
Regards!
A student is examining a chemical reaction the student notes that the reaction requires 7.14 kcal mol energy per biomlecule synthesized the reaction itself produces 21.42 kcal mol energy the sutdent argues this is enough energy to make 3 biomecules. What error has the student made in the analysis?
a. The studentiras not remembered the Second Law of Thermodynamics.
b. The students has not remembered the First Law of Thermodynamics.
c. The student has made a simple calculation error
d. The student has made a conversion error
