Answer: The volume of 0.300 M NaF required is 59.6 ml
Explanation:
According to the dilution law,
[tex]C_1V_1=C_2V_2[/tex]
where,
[tex]C_1[/tex] = concentration of concentrated NaF solution = 0.300 M
[tex]V_1[/tex] = volume of pure concentrated Na F solution = ?
[tex]C_2[/tex] = concentration of diluted NaF solution= 0.0715 M
[tex]V_2[/tex] = volume of diluted NaF solution= 250.0 ml
[tex]0.300\times x=0.0715\times 250.0[/tex]
[tex]x=59.6ml[/tex]
Thus the volume of 0.300 M NaF required is 59.6 ml
The shark and remora have a relationship that benefits the remora but neither helps nor harms the shark What type of relationship is this
Silicon has three naturally occurring isotopes. Based on the AVERAGE atomic mass, which is 28.085, what is the likely mass of the most common isotope
26
27
28
29
30
The most common isotope : Si-28, ²⁸Si
Further explanationThe elements in nature have several types of isotopes
Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
In determining the mass of an atom, as a standard is the mass of 1 carbon-12 atom whose mass is 12 amu
An atomic mass unit = amu is a relative atomic mass of 1/12 the mass of an atom of carbon-12.
The 'amu' unit has now been replaced with a unit of 'u' only
Mass atom X = mass isotope 1 . % + mass isotope 2.% ..
The most common isotope is an isotope with a very large percentage which is indicated by the mass number closest to the average atomic mass
So from the above isotopes that are close to their average mass number is the Si-28
can someone please help me it's already past due
Answer:
Q1: 4
Q2: 2
Q3: 2
Explanation:
Calculate the pH of the buffer that results from mixing 60.0 mL of 0.25 M HCHO2(pKa= 3.74) and 15.0 mL of 0.500 M NaCHO
Answer:
[tex]pH=3.44[/tex]
Explanation:
Hello.
In this case, since the formic acid (HCHO2) is a weak acid and it is mixed with its conjugate base (CHO2⁻) in the form of NaCHO2, we can compute the pH via the Henderson-Hasselbach equation:
[tex]pH=pKa+log(\frac{[Base]}{[Acid]} )[/tex]
Whereas the concentration of both acid and base are computed considering final total volume of 75.0 mL after adding the volume of each solution as shown below:
[tex]n_{base}=0.500mol/L*0.0150L=7.50x10^{-3}mol\\\\n_{acid}=0.25mol/L*0.0600L=1.5x10^{-2}mol[/tex]
And the resulting concentrations upon the final volume:
[tex][Base]=\frac{7.50x10^{-3}mol}{0.0750L}=0.1M[/tex]
[tex][Acid]=\frac{1.5x10^{-2}mol}{0.0750L}=0.20M[/tex]
Thus, the pH is:
[tex]pH=3.74+log(\frac{0.10M}{0.20M} )\\\\pH=3.44[/tex]
Best regards.
Solid calcium reacts with solid sulfur to produce solid calcium sulfide?
Answer:
Ca + S -----> CaS
Explanation:
Since it is balanced you don't need to multiply it any more.
Solid calcium reacts with solid sulfur to produce solid calcium sulfide. The balanced equation for this reaction can be given as Ca + S → CaS.
What is balanced equation?An equation for just a chemical reaction is said to be balanced if both the reactants as well as the products have the same number of atoms and total charge for each component of the reaction. In other words, both sides of a reaction have an equal balance of mass and charge.
The ingredients and outcomes of a chemical reaction are listed in an imbalanced chemical equation, but the amounts necessary to meet the conservation of mass are not specified. Solid calcium reacts with solid sulfur to produce solid calcium sulfide. The balanced equation for this reaction can be given as Ca + S → CaS.
Therefore, the balanced equation for this reaction can be given as Ca + S → CaS.
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What would happen if a mixture of benzoic acid (C6H5CO2H) and chloroethane (CH3CH2Cl) is added to a separatory funnel containing H2O and CH2Cl2
Answer:
Both benzoic acid and chloroethane will be extracted into the CH2Cl2 layer. a small amount of the benzoic acid may be found in the water layer.
Explanation:
Both benzoic acid and chloroethane are more soluble in organic solvents. benzoic acid can only be soluble in water when it is converted into a benzoate.
Hence, only a small amount of the benzoic acid may be found in the water layer. Both benzoic acid and chloroethane are largely extracted into the dichloromethane layer.
A student performs an investigation to determine which substance's addition to water, salt, or sugar would cause a greater increase in boiling point. Which step would the student complete after analyzing data? (2 points) Decide how much salt, sugar, and water to use in each of the tests Look on the Internet for ideas about types of tests to perform Predict whether a certain amount of salt or sugar will cause a greater increase State a conclusion about which substance increases the boiling point more
Answer:
State a conclusion about which substance increases the boiling point more
Explanation:
In scientific experiments, after the data has been collected and analyzed, valid conclusions can now be drawn from the analysis of data.
The process of experimental design involves;
i) observation
ii) formulation of hypothesis
iii)experiments
iv) analysis
v) conclusion
When the results are analysed and the hypotheses are tested, valid conclusions can now be drawn from data analysis.
In this case, analyzing the results show substances that increase the boiling point more than others.
what is the hypothesis in the atomic dating game?
Answer:
it will fail
Explanation:
Imagine an element that has 15 protons, 16 neutrons, and 18 electrons. Which of the following would NOT be considered an isotope of this element? *
15 protons, 16 neutrons, and 15 electrons
15 protons, 17 neutrons, and 15 electrons
15 protons, 15 neutrons, and 18 electrons
Answer:
A: 15 protons, 16 neutrons, and 15 electrons
Explanation: An isotope of an element is when neutrons are taken away from the nucleus, or added to the nucleus.
If you change the amount of protons in the nucleus, not only will the charge become positive due to their being one more proton than an electron, but the atom will change to a new element, Sulfur. If you change the electron count, that will just affect how prominent the negative charge is on the atom, whether it be more negative by adding an electron, or more postitive by removing an electron. Therefore, the amount of neutrons that you add to the nucleus of an atom, will change the isotope of the atom, and that's why the answer is A because every other answer changes the neutron count other than A.
The following have been the main reasons for change in the scientific
views of the origin of the Universe over time:
O Technology
O Evidence
O The creation of new elements in a lab setting
Both Technology and Evidence
O All of the above
Answer:
all of the above
Explanation:
How does the scientist benefit society?
O A. The scientist uses specialized training to direct nonscientific
thought in society.
B. The scientist uses specialized training to tell society which
problems need to be fixed.
O C. The scientist uses specialized training to force governments to act
only in ways that benefit society.
D. The scientist uses specialized training to help solve problems
faced by society.
Answer: I believe it’s D
Explanation:
1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁴
Answer:
umm im just here for the points, im sorry if i knew i would answer it i dont take chemistry
Explanation:
Which element is a nonmetallic liquid at room
temperature?
(1) hydrogen
(2) oxygen
(3) mercury
(4) bromine
Answer:
According to my research there are 2 answers present.
Explanation:
Bromine as well as mercury is a nonmetallic liquid at room temperature
A student prepared a stock solution by dissolving 20.0 g of NaOH in enough water to make 150. mL of solution. She then took 15.0 mL of the stock solution and diluted it with enough water to make 65.0 mL of a final solution. What is the concentration of NaOH for the final solution?
A) O. 411 M
B) 0.534 M
C) 1.87 M
D) 2.43 M
Answer:
0.7692 M
Explanation:
[tex]m[/tex] = Mass of sample = [tex]20\ \text{g}[/tex]
[tex]V[/tex] = Volume of solution = [tex]150\ \text{mL}[/tex]
[tex]V_1[/tex] = Initial volume taken out of the stock solution = [tex]15\ \text{mL}[/tex]
[tex]Mo[/tex] = Molar mass of NaOH = [tex]39.997\ \text{g/mol}[/tex]
[tex]V_2[/tex] = Final volume of solution = [tex]65\ \text{mL}[/tex]
Molarity of stock solution is given by
[tex]M_1=\dfrac{m}{MoV}\\\Rightarrow M_1=\dfrac{20}{39.997\times 0.15}[/tex]
[tex]M_1V_1=M_2V_2\\\Rightarrow M_2=\dfrac{M_1V_1}{V_2}\\\Rightarrow M_2=\dfrac{\dfrac{20}{39.997\times 0.15}\times 0.015}{0.065}\\\Rightarrow M_2=0.7692M[/tex]
The concentration of NaOH for the final solution is 0.7692 M
What is the half-life of radon-222 if a sample initially contains 120.0 mg and only 18.1 mg after 12.3 days?
Answer:
[tex]t_{1/2}=4.51days[/tex]
Explanation:
Hello.
In this case, since the kinetics of radioactive decay in terms of initial and final amounts, elapsed time and half-life is:
[tex]A=A_0\times2^{-t/t_{1/2}}[/tex]
we can compute the half time as shown below:
[tex]2^{-t/t_{1/2}}=\frac{A}{A_0}\\\\-\frac{t}{t_{1/2}} ln(2)=ln(\frac{A}{A_0})\\\\t_{1/2}=-\frac{t\times ln(2)}{ln(\frac{A}{A_0})}[/tex]
Plugging in the known amounts and elapsed time, we obtain:
[tex]t_{1/2}=-\frac{12.3\times ln(2)}{ln(\frac{18.1}{120})}\\\\t_{1/2}=4.51days[/tex]
Best regards!
During photosynthesis, plants produce "food" for themselves. When animals eat plants, they take in energy that originally came from?
A.A seed
B. the soil
C. water
D. the sun
A solution of potassium sulfide is mixed with a solution of magnesium bromide. Identify the two possible products.
A. MgBr
B. KS
C. K2S
D. K2Br2
E. MgBr2
F. MgS
G. KBr
Write the formula of the insoluble product from part 1. 8 KBr.
Answer:
G. KBr
F. MgS
MgS is the insoluble product.
Explanation:
When 2 salts as potasium sulfide, K₂S and magnesium bromide, MgBr₂ react, a double replacement reaction occurs where cations (K⁺ and Mg²⁺) exchange places, as follows:
K₂S + MgBr₂ → 2 KBr + MgS
Thus, the two possible products are:
G. KBr
F. MgS
Now, based on solubility rules:
All compounds containing alkali metal ions (As K⁺) are solubles in water. KBr is soluble
And all sulfides except calcium, strontium and barium sulfide are insoluble.
Thus, the insoluble product is:
MgS
What is Kp for the reaction, 3 NO(g) ⇌ N2O(g) + NO2(g)
a) ∆H =-155.5 kJ/mol
b) ∆S =-171.5 J/mol K
c) ∆G =-104.4 kJ/mol
Answer:
For the reaction 3NO(g) ⇌ N2O(g) + NO2 (g) at equilibrium, Kp = 1.3×10^18 .
Explanation:
Predict the charge of the most stable ion of sodium
What have scientists learned about the cuttlefish through observation?
A. The cuttlefish should not be hunted for food,
B. The cuttlefish got its name from an Old English word.
C. The cuttlefish was valuable to the Romans because it could
produce a brown ink.
O D. The cuttlefish can change its appearance to blend into its
environment.
In an experiment, a model can help a scientist
A. test a situation that is otherwise too complex to observe
B. make the experimental setup match reality as closely as possible
C. create a hypothesis
D. draw a conclusion from experimental results
Answer:
B
Explanation:
the model is to represent something in reality
In an experiment, a model can help a scientist make the experimental setup match reality as closely as possible.
What is an experiment ?An empirical technique that settles conflicting models or hypotheses is called an experiment. Additionally, experiments are used by researchers to confirm or refute new or current theories.
Because experiments are used to verify a hypothesis, an axiom, or phenomena with a theoretical foundation in order to transform it into a law or a theorem like Newton laws, they play a crucial role in the progress of science.
Science uses experiments in many different ways. One of its key functions is to test hypotheses and serve as the foundation for scientific knowledge. It may also indicate the need for a new theory by refuting an established hypothesis or by revealing a new phenomenon that requires an explanation.
Thus, option B is correct.
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name the gas that is largely responsible for the acid rain phenomena
Answer:
sulfur dioxide
Explanation:
The last column of the periodic table contains the noble gases, elements that do not easily form chemical bonds. why don’t these gases tend to form chemical bonds?
PLS HELPPP I WILL MARK BRAINLESY
which diagram best represents the type of plate movement that results in the mountains
Answer:
I think it’s D.
Explanation:
A runner has a mass of 60 kg and a velocity of 0 m/s. What is her momentum?
Answer:
The answer is 0 kg m/sExplanation:
The momentum of an object can be found by using the formula
momentum = mass × velocity
From the question the momentum of the runner will be 0 kgm/s since the runner's velocity is 0
Hope this helps you
1) Calculate the density of a rock with a mass of 267 grams and a volume of 968 cm?
Answer:
.2758 g/cm
Explanation:
density = mass / volume
267/968 = .2758
The molar mass of M(OH)2, formed by the hypothetical metal M, is 199.416 g/mol. What is the molar mass of the corresponding sulfide?
Assume that the charge of the metal doesn't change.
Provide your answer in decimal notation rounded to two decimal digits (i.e. to the hundredths place).
Answer:
197.48 g/mol
Explanation:
We must first discover the relative atomic mass of M;
From;
M + 2[ 16 + 1 ] = 199.416
M + 34 = 199.416
M = 199.416 - 34
M= 165.416
Since the sulphide is MS
molar mass = 165.416 + 32.065
molar mass= 197.48 g/mol
The molar mass of the corresponding sulfide is 197.48 g/mol
Calculation of molar mass:Since The molar mass of M(OH)2, formed by the hypothetical metal M, is 199.416 g/mol.
Now the atomic mass of M should be
M + 2[ 16 + 1 ] = 199.416
M + 34 = 199.416
M = 199.416 - 34
M= 165.416
Since the sulphide is MS
So,
molar mass = 165.416 + 32.065
molar mass= 197.48 g/mol
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how many molecules are there in 24 grams of FeF3
Answer:
1.2x1023 molecules
hope this helped!
Explanation:
1227.6
during witch age range do most girls bodies begin to grow hair under there under arms
select one of these options A. 5-9 b. 8-14 c. 15-18 d. 19-25 PLS HELP ASAP
Answer:
I think it's B, when hair begins to grow.
Explanation:
Good luck! <3
which element would have the highest ionization energy? Na, Mg, Al, P
Answer:
The first ionization energy varies in a predictable way across the periodic table. The ionization energy decreases from top to bottom in groups, and increases from left to right across a period. Thus, helium has the largest first ionization energy, while francium has one of the lowest.
Explanation:
