It takes 53.0 J to raise the temperature of an 11.0 g piece of unknown metal from 13.0∘C to 24.3 ∘C. What is the specific heat for the metal?
Answer:
Heat absorbed = mS△T
51 = ( 8.2/1000)Kg ×S (11.5)
51×1000= 8.2 (11.5)S
S = 51000/94.3
S = 540.8 J/kg K
The acid ionization equilibrium for the weak acid HF is represented by the equation above. To prepare a buffer with a pH=3.50, a student needs to mix 250.mL of 0.100MHF and 250.mL of 0.100MKF. If the student mistakenly mixes 250.mL of 0.0500MHF and 250.mL of 0.0500MKF, which of the following is the result of this error?
The buffer will have a lower capacity because of the smaller number of moles of HF and F− available to react if an acid or base is added.
The buffer will have a lower capacity because of the smaller number of moles of H F and F with a negative 1 charge available to react if an acid or base is added.
The buffer will have a lower capacity because the smaller amount of HF and F− will lower the pH of the buffer, and buffers of lower pH have a lower buffer capacity.
The buffer will have a lower capacity because the smaller amount of H F and F with a negative 1 charge will lower the p H of the buffer, and buffers of lower p H have a lower buffer capacity.
The buffer will have a higher capacity because a larger proportion of HF and F− will ionize at lower concentrations, resulting in the neutralization of any added acid or base.
The buffer will have a higher capacity because a larger proportion of H F and F with a negative 1 charge will ionize at lower concentrations, resulting in the neutralization of any added acid or base.
The buffer will have the same capacity because the large volume of the buffer solution dilutes any added acid or base
Answer:
4
Explanation:
From the options provided the result of the error is ( A ) ; The buffer will have a lower capacity because of the smaller number of moles of HF and F⁻ available to react if an acid or base is added.
Considering the acid ionization equilibrium for the weak acid HF.
A buffer solution is a solution that its PH value remains unchanged when a small amount of acid or base to added to the solution, therefore when the moles of acid or base present in the buffer solution is high enough the buffer solution will have a high buffer capacity. from the mistake of the student the number of moles present is lesser which means that the buffer solution will have a lower capacity
Hence the buffer will have a lower capacity because of the smaller number of moles of HF and F⁻ available to react is an acid or base is added.
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g Consider (12.5 A) micro-grams of a radioactive isotope with a mass number of (78 B) and a half-life of (32.6 C) million years. If energy released in each decay is 32.6 keV, determine the total energy released in joules (J) in 1 (one) year. Give your answer with three significant figures.
Answer:
Energy released = 18.985 J
Explanation:
The exponential decay of radioactive substance is given by -
N(t) = N₀ [tex]e^{-kt}[/tex]
where
N₀ = initial quantity
k = decay constant
Half life, [tex]t_{1/2} = \frac{ln 2}{k}[/tex]
⇒[tex]k = \frac{ln 2}{t_{1/2} }[/tex]
Given,
N₀ = 12.5 + 3 = 15.5 × 10⁻⁶ gm
[tex]t_{1/2}[/tex] = 32.6 + 18 = 50.6 × 10⁶ years
So,
[tex]k = \frac{ln 2}{50.6 * 10^{6} }[/tex] = 1.361 × 10⁻⁸ year⁻¹
Now,
N(1) = 15.5 × 10⁻⁶ [tex]e^{-1.361*10^{-8} *1}[/tex]
= 15.49999978904
Now,
Substance decayed = N₀ - N(t)
= 15.5 × 10⁻⁶ - 15.49999978904 × 10⁻⁶
= 21.095 × 10⁻¹⁷ kg
⇒Δm = 21.095 × 10⁻¹⁷ kg
So,
Energy released = Δmc²
= 21.095 × 10⁻¹⁷ × 3 ×10⁸ × 3 × 10⁸
= 189.855 ×10⁻¹
= 18.985 J
⇒Energy released = 18.985 J
The three elements in the photos all belong to the same group, or column, of the periodic table. These elements all produce salts when they react
with metals. What are some differences between these elements?
Choose all that apply.
Answer:
The answer is Color,atomic mass, state of matter of each element.
Explanation:
BRAINLIEST if answered correctly
Answer:
I would choose E
Explanation:
Chemical reactions occur when chemical bonds between atoms are formed or broken. The substances that go into a chemical reaction are called the reactants, and the substances produced at the end of the reaction are known as the products
web-
2. Given the following equation: 2 KCIO3 ---> 2 KCl + 3 O2
How many moles of O2 can be produced by letting 12.00 moles of KClO3 react?
show work. helppp asap
Answer:
18 moles of O2 can be produced by letting 12.00 moles of KClO3 react
Explanation:
The balanced equation is
2KCIO3 ---> 2 KCl + 3 O2
As per the reaction,
2 mole of KClO3 produces 3 mole of O2 gas
Hence, 12 moles of KClO3 will produce [tex]12*\frac{3}{2} =18[/tex]
Hence, 18 moles of O2 can be produced by letting 12.00 moles of KClO3 react
Please write the answer in format below
Answer:
0.95 L
Explanation:
Step 1: Given data
Concentration of the Mg(NO₃)₂ solution (C): 0.32 M (0.32 mol/L)
Mass of Mg(NO₃)₂ (solute): 45 g
Step 2: Calculate the moles corresponding to 45 g of Mg(NO₃)₂
The molar mass of Mg(NO₃)₂ is 148.33 g/mol.
45 g Mg(NO₃)₂ × 1 mol Mg(NO₃)₂ /148.33 g Mg(NO₃)₂ = 0.303 mol Mg(NO₃)₂
Step 3: Calculate the volume of solution that contains 0.303 moles of Mg(NO₃)₂
The concentration of the solution is 0.32 M, that is, there are 0.32 moles of Mg(NO₃)₂ per liter of solution.
0.303 mol Mg(NO₃)₂ × 1 L Solution / 0.32 mol Mg(NO₃)₂ = 0.95 L
Explain the difference between wavelength and frequency
Answer:
Wavelength (typically measured in nanometers) is the distance between two points in a wave.Frequency (typically measured in Hertz) is the number of waves in a specific time . Frequency and wavelength have both direct and inverse relationships. The crucial difference between frequency and wavelength is that frequency shows the total number of wave oscillations in a given time. As against wavelength specifies the distance between two specific points of a wave.
Explanation:
Frequency is how often something changes per second be it amplitude of a voltage on a wire or be it the bobbing back and forth of a bobblehead. Frequency is how often something moves up and down in a second. If a bobble head moves forward and backward in one second then it has a bobbling frequency of 1 Hertz (Hz). The unit of frequency is Hertz (Hz) or # of cycles or oscillations per second. A wavelength is measured in distance like meters (m). For photons or light or radiowaves the equation is wavelength=speed of light/frequency.
Answer:
Wavelength (typically measured in nanometers) is the distance between two points in a wave, while frequency is how often something changes per second be it amplitude of a voltage on a wire or be it the bobbing back and forth of a bobblehead.
the first three process involved in water purification can be summarize as
Answer:
Aeration,flocculation,coagulation.
Explanation:
Answer:
.
Explanation:
The combustion of coal, a fossil fuel, to produce electrical energy produces a by-product, sulfur dioxide, which is emitted into the atmosphere. Sulfur dioxide will mix with the components in the atmosphere to produce _____.
Forest Fires
Global warming
Acid Rain
Algae growing in ponds and lakes
Psychology is the study of the human brain. A psychoanalyst is a person who
analyzes people's minds. What does the prefix psycho-mean?
A. Related to the brain
B. Related to studying
C. Related to science
D. Related to analysis
true or false atoms can be made up of just one type of atom
Answer:
false
Explanation:
A compound has the combined properties of the elements from which it is made. Atoms show the macro properties of an element.
Lion 7
Which of the following is a valid science lab safety guideline?
omplete
s out of
Select one:
O a. Do not eat or drink anything while in the lab.
ag
tion
O b. Wear a drawstring hoodie to protect yourself from chemicals.
O c. Wait to clean up any spills until you complete the lab
procedure.
O d. Change the lab procedure if necessary to improve the
experiment.
Check
Answer:
A.
Explanation:
You should NEVER eat or drink anything in a lab area. You never know what chemicals or gases are in the lab, and they can harm you.
Wearing a drawstring hoodie won't protect you from chemicals.
Don't wait to clean up chemicals, immediately get a teacher and clean it up (follow the teachers instructions). You never know what has spilled, and if it is harmful or not, or if there is a certain procedure to clean it up.
Don't change the equipment in the middle of an experiment. This can tamper with your results, and depending on what you are working with, this can be dangerous.
2) A balloon was inflated to a volume of 5.0 liters at a temperature of
7.0°C. It landed in an oven and was heated to 147°C. What is its new
volume?
Answer:
6.12 L
Explanation:
Given that,
Initial volume, V₁ = 5 L
Initial temperature, T₁ = 7.0°C = 343 K
Final temperature, T₂ = 147°C = 420 K
We need to find its new volume. The relation between volume and temperature is given by :
[tex]\dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}\\\\V_2=\dfrac{V_1T_2}{T_1}\\\\V_2=\dfrac{5\times 420}{343}\\\\V_2=6.12\ L[/tex]
So, the new volume is 6.12 L.
It’s due in 3 minutes please help
Answer:
The Answer is gonna be Indroduction of non-native plant species
When naming bases, you add ___ to the end
Answer:
hydroxide ion
Explanation:
because base produce hydroxide ion when dissolved in water
See if you can complete the following table using only what is on this page. Hint. Two of the entries are for the same element.
Element
Symbol
Nuclear
Symbol
Atomic Mass
Protons Neutrons
Electrons in
Number Number
Neutral Atom
57
82
138
57
ola
Fe
59
26
Answer and Explanation:
The empty spaces should be completed step-by-step as follows:
First line:
Element symbol: La (it is the corresponding element for the atomic number 57)
Mass number = Atomic number + Neutrons = 57 + 82 = 139
Nuclear symbol: ¹³⁹₅₇ La because the atomic number is 57 and mass number is 139.
Protons: 57 (is equal to the atomic number for a neutral atom)
Electrons in neutral atom = Atomic number = 57
Second line:
Element symbol: La (it is the corresponding element for the atomic number 57 and mass number 138)
Atomic number: 57 (from the Periodic Table, for La)
Mass number = 138 (from the nuclear symbol)
Protons: 57 (is equal to the atomic number for a neutral atom)
Neutrons = Mass number - Atomic number = 138 - 57 = 81
Electrons in neutral atom = Atomic number = 57
Third line:
Atomic number: 26 (from the Periodic Table, for the element Fe)
Protons: 26 (is equal to the atomic number for a neutral atom)
Neutrons = Mass number - Atomic number = 59 - 26 = 33
Nuclear symbol: ⁵⁹₂₆ Fe because the atomic number is 26 and mass number is 26.
PLEASE HELP IF YOU KNOW I WILL MARK BRAINLIEST!!! A LOT OF POINTS!!
What is the solubility in Molarity of Ag2SO4 in a 0.1M solution of Sodium Sulfate at 25C?
Answer:
0.0039 mol/L
The molar solubility is 0.0039 mol/L, thus the common ion effect has reduced the solubility from 0.016 mol/L for Ag2SO4 in pure water to 0.0039 mol/L in the Na2SO4 solution.
Explanation:
1. You and a friend are hiking through a canyon. You tell your friend that the rock layers in the canyon are all different ages, and you can
tell which rock layers are the oldest and which are the youngest. She picks four different rock layers on the canyon wall, as shown in the
photograph
Which layer is the youngest?
A. Layer 1
O B. Layer 2
C. Layer 3
D. Layer 4
Answer:
its number 4 D layer 4
Explanation:
just look at it look at the colors so that's how you know and plus it just old
Answer:
From what I gathered from researching, I would say that Layer 2 is the correct answer to the question you asked.
Explanation:
The reason I'd say it is Layer 2 is because the lower you look in a canyon, the farther back you look in time. Over that canyon's history, more layers are added on top of the rock and ground as erosion and weathering happen.
Layer 2 is the highest up, which means that it was added the most recent of the other layers. Although there are more things that could maybe be taken to account, the best answer I see from what information you were given in this question... Layer 2 is the correct answer.
Hope that helps!
10. Although lidocaine is marketed as its hydrochloride salt, it doesn’t exhibit the same level of physiological activity as the free amine. The free amine is more lipophilic and diffuses across a neuron cell membrane more rapidly than the ionic salt, resulting in a more rapid onset of anesthesia. Therefore, sodium bicarbonate (NaHCO3) is added to a solution of lidocaine prior to injection. How does the addition of sodium bicarbonate promote a faster anesthetic effect?
Answer:
Bicarbonate neutralizes the acidity of Lidocaine and hence reduce the pain
Explanation:
Alkalinization by addition of sodium bicarbonate causes buffering of local anesthetics and hence produce faster anesthetic effect such as pain control, pain reduction while injecting the patient and faster onset of local anesthetics.
Lidocaine along with epinephrine results into acidic compound wit respect to subcutaneous tissue. Hence, when bicarbonate is added, it neutralizes the acidity of Lidocaine and hence decrease the pain.
HELP PLEASEEEEEE ASAP
A condition in which bones become weak and brittle.
The body constantly absorbs and replaces bone tissue. With osteoporosis, new bone creation doesn't keep up with old bone removal.
thus 2) is correct.
a disease in which bone tissue becomes breakable and thin.
if it helps don't forget to like and Mark me
Q3: Match the column A with Column B and write answer in Column C
Answer:
ok
Explanation:
1d
2c
3b
4a
Question 3
Which of the objects on the shelf has the greatest inertia?
10 kg
5 kg
2kg
a
b
2 kg
5 kg
10 kg
С
d
The all have the same inertia
Using the weather radar map shown here, infer at which lettered point the most likely tornado formation and damage would
occur.
es )
A)
А
B)
B
C С
D
D
Answer:
c
Explanation:
this is because it makes sense
Answer:
d
Explanation:
What is the energy of an electron in a Li+ ion when an electron moves from n = 2 to n =3?
Answer:
The question wants you to determine the energy that the incoming photon must have in order to allow the electron that absorbs it to jump from
n
i
=
2
to
n
f
=
6
.
A good starting point here will be to calculate the energy of the photon emitted when the electron falls from
n
i
=
6
to
n
f
=
2
by using the Rydberg equation.
1
λ
=
R
⋅
(
1
n
2
f
−
1
n
2
i
)
Here
λ
si the wavelength of the emittted photon
R
is the Rydberg constant, equal to
1.097
⋅
10
7
m
−
1
Plug in your values to find
1
λ
=
1.097
⋅
10
7
.
m
−
1
⋅
(
1
2
2
−
1
6
2
)
1
λ
=
2.4378
⋅
10
6
.
m
−
1
This means that you have
λ
=
4.10
⋅
10
−
7
.
m
So, you know that when an electron falls from
n
i
=
6
to
n
f
=
2
, a photon of wavelength
410 nm
is emitted. This implies that in order for the electron to jump from
n
i
=
2
to
n
f
=
6
, it must absorb a photon of the same wavelength.
What transition energy corresponds to an absorption line at 502 nm?
A. 4.56 x 10-19
B. 1.76 10-19
C. 2.53 x 10-19
D. 3.96 10-19 J
Answer:
D 3.96 10-19J
Explanation:
I took the test
A 5.0 L air sample at a temperature of -50°C has a pressure of 800.00 mmHg. What
the new pressure if the temperature is raised to 100°C and the volume expands to 7.0
L?
Answer:
956 mmHg
Explanation:
The combined gas law states that P1V1/T1 = P2V2/T2 when moles of gas are constant. We're looking for P2, so solve all of that for P2. Make sure you convert your temperatures to Kelvin by adding 273 to the Celsius temperatures.
P2 = P1V1T2/T1V2
P1 = 800.00 mmHg
V1 = 5.0 L
T2 = 100 + 273 = 373 K
T1 = -50 + 273 = 223 K
V2 = 7.0 L
P2 = (800.00 mmHg)(5.0 L)(373 K) / (223 K)(7.0 K) = 956 mmHg
What is the molarity (M) of a solution that has 0.50 moles of solute dissolved in 1.0
liter of solution?
Answer:
it is 0.50=0.5 M
Explanation:
Molarity definition is measure the concentration of solution.
and the rule is
molarity(M)= moles of solute/volume of solution in liters
Ex: 2.1 M MgCl2= 2.1 mole MgCl2/ L MgCl2 solution
A student mixes 36.0 grams of silver nitrate solution with 30.0 grams of sodium chromate solution. The mass of the products, which includes the resulting solution and precipitate, is equal to 66.0 grams. Which of the following best explains these results
Answer:
Explanation:
The law of multiple proportions.
In which way do buffalos protect themselves from predator animals such as lions
Answer: Both males and females have sharp, curved horns extending from the sides of their heads which are used to defend themselves against predators.
Explanation:
