Answer:
18
Explanation:
36 times 0.5
A sample of 6.44 g of napthalene (C10H8) is dissolved in 80.1 g of benzene (C6H6). Calculate the percent by mass of napthalene in this solution.
Answer:
7.44%
Explanation:
[tex]\frac{6.44}{6.44+80.1} *100=7.44[/tex]
A Beer's Law Plot of sample A gives a slope equal to 1.2 M-1cm-1. Calculate molar concentration of this sample at a wavelength of 420 nm and an absorbance reading of 0.23 in a 1 cm cuvette.
Answer:
[tex]0.192\ \text{M}[/tex]
Explanation:
A = Absorbance of solution
E = Molar absorptivity
l = Length of cuvette = 1 cm
c = Concentration of solution
Beer's law is given by
[tex]A=Elc[/tex]
The equation of a straight line is given by
[tex]y=mx+c[/tex]
Comparing the above equations we get
Value on [tex]y[/tex] axis = A = Absorbance of solution = 0.23
[tex]m[/tex] = Slope of line = El = Molar absorptivity multiplied with length = [tex]1.2\times 1\ \text{M}^{-1}[/tex]
[tex]x[/tex] = Value of x axis = c = Concentration of solution
So we get
[tex]c=\dfrac{A}{El}\\\Rightarrow c=\dfrac{0.23}{1.2\times 1}\\\Rightarrow c=0.192\ \text{M}[/tex]
The molar concentration of the sample is [tex]0.192\ \text{M}[/tex]
Which of the following has a nonpolar bond? *
02
HCI
NH3
CH4
Answer: CH4
Explanation:
BRAINLESS PLEASE
Answer:
O₂
Explanation:
The example of the compound or the molecule that forms a non-polar bond is oxygen gas.
Oxygen gas has a formula of O₂
Since this is a homonuclear molecule, the two bonding atoms have the same kind of electronegativity. The difference is therefore zero. In such a molecule, there is equal sharing of the electron pair between the atoms and no electrostatic charge on the molecule.how many neutrons make up one of these potassium atoms?
Answer:
20 Neutrons
Explanation:
The element of potassium has the symbol K. The nucleus of an atom of potassium contains 19 protons and 20 neutrons. I hope that answer helps xx
For the following reaction at equilibrium SO3(g) + NO(g) = SO2(g) + NO2(g)It is found that [SO2] = 0.70 M and [NO] = 1.20 M. Calculate the equilibrium constant for the readction knowing that the initial concentration were [SO3] = 2.55 M and [NO] = 1.90 M.
Answer:
[tex]K=0.14[/tex]
Explanation:
Hello!
In this case, for the undergoing chemical reaction, we can write the equilibrium expression via:
[tex]K=\frac{[SO_2][NO_2]}{[SO_3][NO]}[/tex]
Whereas the equilibrium concentration of both SO3 and NO are 2.55 M and 1.90 M respectively, it means that the extent of reaction [tex]x[/tex] is:
[tex]x=1.90M-1.20M=0.7M[/tex]
Because the equilibrium expression in terms of the reaction extent is:
[tex]K=\frac{x*x}{([SO_3]_0-x)([NO]_0-x)}[/tex]
It means that the concentration of SO3, NO, SO2 and NO2 at equilibrium are:
[tex][SO_3]=2.55M-0.70M=1.85M[/tex]
[tex][NO]=1.20M[/tex]
[tex][SO_2]=0.70M[/tex]
[tex][NO_2]=0.70M[/tex]
Thus, the equilibrium constant for such reaction is:
[tex]K=\frac{0.70*0.70}{1.85*1.90}\\\\K=0.14[/tex]
Best regards!
Examples of solutions can be:
O A. a solid dissolved in a liquid
O B. gas mixed with a liquid
O C. liquid mixed with a liquid
OD. all of the the above
Answer:
B. gas mixed with a liquid
Explanation:
because:
A. a solid can't dissolve in a liquid.
C. two liquids mixed isn't a solution
D. Not All of the above for sure.
Examples of solutions can be all of the above. The correct option is D.
What is a solution?A solution is made when a solute is mixed with a solvent. The solution can be a liquid, solid, or gas. The solution is made when the solute is fully mixed with the solvent. The solute is the substance that gets mixed, and the solvent is the base in which the solute gets dissolved.
So, a solid dissolved in a liquid, gas mixed with a liquid, or a liquid mixed with a liquid, the energy statement is true for a solution.
Examples of a solution are sugar dissolved in water when water mix with soda and state gets mixed with water or another gas.
Thus, the correct options are D. all of the the above.
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A buffer is prepared by mixing 204.0 mL of 0.452 M HCl and 0.500 L of 0.400 M sodium acetate (NaC2H3O2):
Calculate the pH of the buffer.
How many grams of KOH must be added to 0.500 L of the buffer to change the pH by 0.15 units?
Answer:
pH = 4.89
0.6171g of KOH must be added
Explanation:
Sodium acetate reacts with HCl producing acetic acid as follows:
NaC2H3O2 + HCl → HC2H3O2 + NaCl
That means the moles added of HCl are moles of acetic acid produced and moles of acetate are initial moles - moles of HCl
Moles HCl = Moles acetic acid:
0.204L * (0.452mol / L) = 0.0822 moles acetic acid.
Initial moles sodium acetate:
0.500L * (0.400mol / L) = 0.200 moles
Moles sodium acetate:
0.200 moles - 0.0822 moles = 0.1172 moles sodium acetate
The pH of this buffer (Mixture of a weak acid and its conjugate base) is obtained using H-H equation:
pH = pKa + log [A-] / [HA]
Where pH is pH of the buffer,
pKa is pKa of the buffer (4.74 for acetic acid)
[A-] Moles of sodium acetate -Conjugate base-
And HA moles of acetic acid -Weak acid-
pH = 4.74 + log [0.1172 moles] [0.0822 moles]
pH = 4.89In 0.500L the moles of the buffer are:
0.500L * (0.200moles / 0.704L) = 0.142 moles of buffer
For a pH of 0.15 units more (4.89 + 0.15 = 5.04):
5.04 = 4.74 + log [Acetate] / [Acetic acid]
0.3 = log [Acetate] / [Acetic acid]
1.9953 = [Acetate] / [Acetic acid] (1)
And as:
0.142 = [Acetate] + [Acetic acid] (2)
Replacing (2) in (1):
1.9953 = 0.142 - [Acetic acid] / [Acetic acid]
1.9953 [Acetic acid] = 0.142 - [Acetic acid]
2.9953 [Acetic acid] = 0.142 moles
[Acetic acid] = 0.0474 moles of acetic acid must remain after the addition of KOH.
In the beginning, moles of acetic acid are:
0.0822 moles * (0.500L / 0.704L) = 0.0584 moles.
That means moles added of KOH (Equal to moles of acetic acid that react) are:
0.0584 moles - 0.0474 moles = 0.0110 moles of KOH
In grams (Molar mass KOH = 56.1g/mol):
0.0110 moles KOH * (56.1g/mol) =
0.6171g of KOH must be addedHow many moles of CO are produced when 1.8 moles C reacts?
Express your answer using two significat figures.
5C(s) + 2SO2(g) => CS2(l) +4CO(g)
Answer:
1.44mole of CO
Explanation:
The reaction equation is given as:
5C + 2SO₂ → CS₂ + 4CO
We check to see if the expression is balanced and it is so;
Now;
Given;
1.8mole of C reacted; how many moles of CO are produced;
From the balanced reaction equation:
5 mole of C is expected to produce 4 mole of CO
1.8 mole of C will then produce [tex]\frac{4 x 1.8}{5}[/tex] = 1.44mole of CO
branches of sicence
Answer:
Natural science can be divided into two main branches
Explanation:
life science and physical science. Life science is alternatively known as biology, and physical science is subdivided into branches: physics, chemistry, astronomy and Earth science.
Answer:
Astronomy
Biology
Geology
Chemistry
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The molarity (M) of an aqueous solution containing 22.5 g of sucrose (C12H22O11) in 35.5 mL of solution is ________.
Answer:
1.86 M
Explanation:
From the question given above, the following data were obtained:
Mass of sucrose (C12H22O11) = 22.5 g
Volume of solution = 35.5 mL
Molarity of solution =?
Next, we shall determine the number of mole in 22.5 g of sucrose (C12H22O11). This can be obtained as follow:
Mass of sucrose (C12H22O11) = 22.5 g
Molar mass of C12H22O11 = (12×12) + (22×1) + (16×11)
= 144 + 22 + 176
= 342 g/mol
Mole of C12H22O11 =?
Mole = mass /Molar mass
Mole of C12H22O11 = 22.5 /342
Mole of sucrose (C12H22O11) = 0.066 mole
Next, we shall convert 35.5 mL to litres (L). This can be obtained as follow:
1000 mL = 1 L
Therefore,
35.5 mL = 35.5 mL × 1 L / 1000 mL
35.5 mL = 0.0355 L
Thus, 35.5 mL is equivalent to 0.0355 L.
Finally, we shall determine the molarity of the solution as follow:
Mole of sucrose (C12H22O11) = 0.066 mole
Volume of solution = 0.0355 L.
Molarity of solution =?
Molarity = mole /Volume
Molarity of solution = 0.066/0.0355
Molarity of solution = 1.86 M
Therefore, the molarity of the solution is 1.86 M.
How do you think energy flows in and out of the earth's atmosphere ?
Compare and contrast the applications and benefits of circle graphs and bar charts. Explain
Answer:
A circle graph, or a pie chart, is used to visualize information and data. A circle graph is usually used to easily show the results of an investigation in a proportional manner. Bar graphs are used to compare things between different groups or to track changes over time. However, when trying to measure change over time, bar graphs are best when the changes are larger.
Explanation:
In short, bar graphs are better to keep track of data over long periods of time, and circle graphs are better when you are trying to visualize a specific set of data.
Circle graph can be also be called pie chart, which is more widely used. It is usually made up of a circle, divided into parts or pies. In the divided parts, it is used to differentiate between different data.
Bar charts on the other hand are like graphs having both x and y axis. It is used to represent data with respect to the height of the graph. Each data is divided into different smaller parts on the graph.
Example of what they look like is attached below.
First one is bar chart while the second is a circle graph
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What is the hybridization state on the central N atom in the azide ion, N3−?
Suppose the Cu ions are produced by the reaction of 0.94 g of copper turnings with excess nitric acid. How many moles of Cu are produced?
Answer:
0.0148 moles
Explanation:
Solid copper is oxidized with HNO₃:
Cu + 4HNO₃ → Cu²⁺ + 2 NO₃⁻ + 2H₂O + 2NO₂
Where 1 mole of Cu produce 1 mole of Cu²⁺ when nitric acid is in excess.
Moles of Cu that react (Molar mass Cu = 63.546g/mol):
0.94g * (1mol / 63.546g) = 0.0148 moles of Cu
And moles of Cu²⁺ produced are also:
0.0148 molesIn ethane, C2H6, ethene (ethylene), C2H4, and ethine (acetylene), C2H2, there are direct carbon-carbon bonds. Which one is the shortest?
a. The carbon-carbon bond in ethane's the longest!)
b. The carbon-carbon bond in ethene is the longest
c. The carbon-carbon bond in ethyne is the longest.
d. All of the carbon-carbon bonds have the same length.
Answer:
a. The carbon-carbon bond in ethane's the longest!)
Explanation:
Ethane is a chemical compound that is organic in nature. Its chemical formula is [tex]$C_2H_6$[/tex]. It has two carbon atoms and six of hydrogen atoms that is connected to the carbon atoms.
Ethane is odorless and colorless at the standard temperature and standard pressure.
The carbon to carbon atoms in ethane is connected by a single bond.
The length of single carbon-carbon bond is greater than carbon-carbon double bond and triple bond.
Thus, carbon-carbon bond length in ethane is the longest.
What is the difference between homogeneous and heterogeneous mixtures?
How many grams of oxygen gas will be produced when 2.50 moles of potassium chlorate is decomposed?
Answer:
[tex]m_{O_2}=120gO_2[/tex]
Explanation:
Hello!
In this case, since the decomposition of potassium chlorate is:
[tex]2KClO_3\rightarrow 2KCl+3O_2[/tex]
We can see a 2:3 mole ratio between potassium chlorate and oxygen (molar mass 32.0 g/mol), thus, via stoichiometry, we compute the mass of oxygen that are produced by the decomposition of 2.50 moles of this reactant:
[tex]m_{O_2}=2.50molKClO_3*\frac{3molO_2}{2molKClO_3} *\frac{32.0gO_2}{1molO_2}\\\\m_{O_2}=120gO_2[/tex]
Best regards!
If 15.5 mL of 0.225 M aqueous magnesium chloride is added to 37.5 mL of 0.250 M aqueous lead(II) nitrate, then what mass of lead(II) chloride precipitates?A. 0.485 g.B. 0.971 g.C. 1.94 g.D. 3.888 g.E. 5.82 8 g.
Answer:
B. 0.971 g
Explanation:
When MgCl₂(aq) reacts with Pb(NO₃)₂(aq), PbCl₂(s) and Mg(NO₃)₂(aq) are produced:
MgCl₂(aq) + Pb(NO₃)₂(aq) →, PbCl₂(s) + Mg(NO₃)₂(aq)
Thus, we need to find imiting reactant finding moles of each reactant:
Moles MgCl₂:
15.5mL = 0.0155L * (0.225 mol / L) = 3.49x10⁻³ moles
Moles Pb(NO₃)₂:
37.5mL = 0.0375L * (0.250mol / L) = 9.38x10⁻³ moles
As the ratio of the reactants is 1:1, the moles of PbCl₂ are 3.48x10⁻³ moles.
We need to convert thes moles to mass using molar mass of PbCl₂ (278.1g/mol), thus:
3.48x10⁻³ moles * (278.1g/mol) =
0.968g of PbCl₂ are precipitate
Thus, right answer is:
B. 0.971 gArrange the following compounds in order of increasing acidity, and explain the reasons for your choice of order. Enter your answer in the answer box below. a. 4-nitrophenol b. cyclohexanol c. 2,6-difluorocyclohexanol d. 4-bromophenol
Answer:
(a) > (d) > (c) > (b)
Explanation:
Acidic character is based upon inductive effect of the functional group that are attached to parent chain.
1. Nitro is a -I group which makes phenol acidic due to increased resonance, 2. bromine is a -I group but it is weaker than nitro group
3. phenol is more acidic than cyclohexanol due to resonance stabilization of resonance and among halogen F>Cl>Br>I is the order of acidity
4. cyclohexanol will be weakest as it is not associated with any -I groups here.
so the order of acidity will be
(a). 4-nitropheno > (d). 4-bromophenol > (c). 2,6-difluorocyclohexanol > (b). cyclohexanol
If 0.0806 mol CaCl2 is dissolved in water to make a 0.490 M solution, what is the volume of the solution?
Answer:
0.16 L
Explanation:
From the question given above, the following data were obtained:
Mole = 0.0806 mole
Molarity = 0.490 M
Volume =?
Molarity is simply defined as the mole of solute per unit litre of the solution. Mathematically, it is expressed as:
Molarity = mole /Volume
With the above formula, we can obtain the volume of the solution as illustrated below:
Mole = 0.0806 mole
Molarity = 0.490 M
Volume =?
Molarity = mole /Volume
0.490 = 0.0806/volume
Cross multiply
0.490 × volume = 0.0806
Divide both side by 0.490
Volume = 0.0806 / 0.490
Volume of solution = 0.16 L
Thus, the volume of the solution is 0.16 L.
A solution is a mixture of solute in the solvent. The volume of the solution is 0.16 L.
What is a solution?A solution is a mixture of solute in the solvent.
An example of a solution is a mixture of salt in water.
Given,
Moles = 0.0806 mol [tex]\rm CaCl_2[/tex]
Molarity = 0.490 M
To find: the volume of the solution
[tex]Molarity = \dfrac{n}{V}[/tex]
Putting the values
[tex]0.490 M = \dfrac{ 0.0806}{V}\\\\0.490 M \times V = 0.0806\\\\Divide\; both\;side\; with\; 0.490\\\\V= \dfrac{ 0.0806}{0.490}=0.16 L[/tex]
Thus, the volume so the solution is 0.16 l.
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If you had to choose,
Happiness or Power? (Any type of Power)
Answer:
I will choose Happiness, Happiness, Happiness, Happiness.....
☺️❤️
Explanation:
Why Happiness Matters
It's the feeling of truly enjoying your life, and the desire to make the very best of it. Happiness is the "secret sauce" that can help us be and do our best. Here's what researchers found when they studied happy people: Happy people are more successful.
Scientific evidence suggests that being happy may have major benefits for your health. For starters, being happy promotes a healthy lifestyle. It may also help combat stress, boost your immune system, protect your heart and reduce pain. What's more, it may even increase your life expectancy.
Describe the bodys first line of defense
Answer:
The main function of the immune system is to provide immunity to the body. Immunity is the body's ability to protect itself from the pathogens it is exposed to. Immunity depends on the body's ability to differentiate between things that belong in the body and those that do not. The immune system's first line of defense includes physical and chemical barriers that are always ready and prepared to defend the body from infection.
The skin acts as a barrier against pathogens. Some structures of the first line of defense include the skin, mouth, eyes, ears, nose, and stomach. The skin produces sweat and oil that work together to keep pathogens from the entering the body. Saliva and tears contain substances the can destroy pathogens. The ears and the stomach help fight pathogens.The ears produce ear wax that prevent pathogens from entering the ears. The stomach produces a liquid the kills pathogens.
Mucus is produce by the nose, lungs, throat, and stomach. Mucus traps pathogens. Mucus also prevent pathogens from getting into deep tissues. Anyway, the very first line of defense against any invasion of the human body is a set of physical barriers between the inside of the body and the outer world.
*my notes from edge2020*
Hope this helps ^-^
Name something that has zero thermal energy.
Answer:
When all molecules in a system stop moving completely, there is zero thermal energy
Explanation:
It is impossible to reach though
what ore is turned to finished aluminum
Which elements-O2, Rb, Sb, Pt, Y, Sm, Mn, Rh, Sn, Li-will react (a) with a solution of I to generate I2; (b) with a solution of Ag' to generate Ag; and (c) with a solution of Nat to generate Na?
Answer:
a) O2, Pt, Rh
b) Rb, Y, Sm, Mn, Sn, Li
c)Rb
Explanation:
We must consider the reduction potentials of each of the species in the question.
In (a) above, all the elements whose reduction potential is higher than the redox potential for the oxidation of I^- will react with a solution of I^- to generate I2 as shown above.
In (b) above, all the strong reducing agents can donate electrons to Ag^+ and reduce it to Ag as shown above.
In (c) Rb has a more negative reduction potential than sodium hence it can react with a solution of sodium salt to generate sodium metal.
What is the mass of the oxygen in one mole of calcium phosphate
Answer:
16.00 g/mol
Explanation:
Answer:
16.00 g/mol
Explination:
1 mol of calcium phosphate contains 8 moles of oxygen. From this, we can compute for the amount of oxygen in grams using the molar mass of oxygen, which is 16.00 g/mol.
PLZ HELP TAKING TEST NOW. WILL GIVE BRAINLIEST
Some students decided to do an experiment with a can of pop. They opened the 340 g can of pop and left it open for a day. They then measured the pop can and found it was 332 g. Does this break the law of conservation of mass? Explain why or why not.
1. Change the following into correct scientific notation.
a) 0.03050 =
b) 0.256 x 10°=
c) 25.005 10 =
Answer:
a) 0.03050 = 3.050 × 10-²
b) 0.256 x 10°= 2.56 × 10-¹
c) 25.005 10 = 2.500510 × 10¹
Explanation:
Scientific notations is a way of making very large or very small numbers more comprehensive or simplified. It involves the use of power of ten (10^). The numbers are represented to the power of ten. The following format is used:
a x 10^b
where; a is a number or decimal number between 1 and 10 i.e less than 10 but greater than 1
b is the power of ten
To write a number in scientific notation,
- we move the decimal point right or left depending on whether we're trying to reduce or increase the number
- we count the number of times the decimal point was moved. This serves as the b in the format above.
For example,
a) 0.03050 = 3.050 × 10-²
The decimal point was moved rightward twice. This caused the ^-2 power.
b) 0.256 x 10°= 2.56 × 10-¹
The decimal point was moved rightward once. This caused the ^-1 power.
c) 25.005 10 = 2.500510 × 10¹
The decimal point was moved leftward once. This caused the ^1 power.
what is the iupac name of CH3-CH2CH(CH3)CH2-COOH
Answer:
Butanoic acid.
Explanation:
In the third century B.C., King Hieron of Syracuse asked the famous mathematician Archimedes to determine if his crown was made of pure gold. This was a puzzling problem for Archimedes-he knew how to measure the weight of the crown, but how could he measure the volume? Archimedes solved the problem when he got into his bath and noticed the water spilling over the sides of the tub. He realized that the volume of the displaced water must be equal to the volume of the object placed into the water. Archimedes was so excited by. his discovery that he jumped out of the bath and ran through the streets shouting "Eureka!" a. How can you tell if a crown is made of solid gold? b. Gold is one of the densest substances known, with a density of 19.3 g/mL. If the gold in the crown was mixed with a less-valuable metal like bronze or copper, how would that affect its density? c. What is the relationship between the object density, the liquid density, and the tendency of the object to float? d. From the experimental results obtained by you in the lab of the density of the liquid and the object, could the object float in that liquid? Explain.
Answer:
See explanation
Explanation:
a. I can conclusively tell if the crown was made of gold by measuring its density. First the mass of the crown is measured on a weighing balance. The crown is now put into a given volume of water and the volume of water displaced is accurately measured. The density of the crown is computed as mass/volume of fluid displaced. If the density of the crown is 19.3 g/mL, then it is made of solid gold.
b) When less valuable metals such as bronze or copper is mixed with gold in the crown, the density of the crown decreases and the crown becomes more brittle.
c) An object will float in a liquid when the density of the object is less than the density of the liquid. Hence the tendency of an object to float in a liquid depends on the density of the object and the density of the liquid.
d) Even though i do not know the results from your experiment but as regards the decision as to whether the object will float in the given liquid or not, reference must be made to the measured density of the object as well as the given density of the liquid. If the object is less dense (from values of density obtained from the experiment) than the liquid, then the object will float in the liquid and vice versa.