Answer:
In my Opinion
Explanation:
False. There's no pulley system or activity in a knife.
Purification of copper can be achieved by electrorefining copper from an impure copper anode onto a pure copper cathode in an electrolytic cell. How many hours will it take to plate 19.5 kg of copper onto the cathode if the current passed through the cell is held constant at 38.5 A
Answer: It will take 425 hours to plate 19.5 kg of copper onto the cathode if the current passed through the cell is held constant at 38.5 A.
Explanation:
The half-reaction equation is as follows.
[tex]Cu^{2+} + 2e^{-} \rightarrow Cu[/tex]
According to the standard values, 1 mole of an electron carries 96500 C. Therefore, charge carried by 2 moles of electrons is [tex]2 \times 96500 C[/tex].
Also, atomic mass of Cu is 63.5 g. According to the equation 2 moles of electrons are depositing 63.5 g of Cu.
Hence, charge required to deposit 19.5 kg (1 kg = 1000 g) or 19500 g of Cu is calculated as follows.
[tex]19500 g Cu \times \frac{2 \times 96500 C}{63.5 g Cu}\\= 5.92 \times 10^{7} C[/tex]
Formula used to calculate time is as follows.
[tex]Q = I \times t[/tex]
where,
Q = charge
I = current
t = time
Substitute the values into above formula as follows.
[tex]5.92 \times 10^{7} C = 38.5 \times t\\t = \frac{5.92 \times 10^{7} C}{38.5}\\= 1.53 \times 10^{6} sec[/tex]
As 1 hour contains 3600 seconds. So, converting seconds into hours as follows.
[tex]1.53 \times 10^{6} sec = 1.53 \times 10^{6} sec \times \frac{1 hr}{3600 sec}\\= 425 hr[/tex]
Thus, we can conclude that it will take 425 hours to plate 19.5 kg of copper onto the cathode if the current passed through the cell is held constant at 38.5 A.
1. How does a virus differ from a common cell?
A. It has no nucleus, cell wall, or organelles.
B. It has two nuclei and no cell wall or organelles.
C. A virus has no cell well, no nucleus, and only organelles for
movement.
D. A virus differs from a cell only in shape.
A radioactive sample contains two different types of radioactive nuclei: A, with half-life 5.0 days, and B, with half-life 30.0 days. Initially, the decay rate of the A-type nucleus is 64 times that of the B-type nucleus. When will their decay rates be equal
Answer:
t = 39.42 days
Explanation:
To do this, we need to use the general expression for decay rate:
R = R₀ exp(-λt) (1)
According to the problem, decay rate of A initially is 64 times rate of B, so we can say the following:
A₀ = 64B₀ (2)
The value of λ can be determined using:
λ = ln2 / t(1/2) (3)
Let's calculate first the value of λ for each nuclei:
For A: λ₁ = ln2 / 5 = 0.1286 day⁻¹
For B: λ₂ = ln2 / 30 = 0.0231 day⁻¹
Now, let's write an expression using (1) for each nuclei.
A = A₀ exp(-0.1286t)
A = 64B₀ exp(-0.1286t) (3)
B = B₀ exp(-0.0231t) (4)
We want to know the time when A = B , therefore, we can actually equals (3) and (4) and solve for t:
64B₀ exp(-0.1286t) = B₀ exp(-0.0231t)
64 exp(-0.1286t) = exp(-0.0231t)
ln(64 * exp(-0.1286t)) = ln(exp(-0.0231t))
ln64 + ln(exp(-0.1286t))= -0.0231t
4.1589 - 0.1286t = -0.0231t
4.1589 = (0.1286 - 0.0231)t
t = 4.1589 / 0.1055
t = 39.42 daysSo, in 39 days, the decay rates of A and B will be the same.
Hope this helps
What are the missing coefficients for H3PO4 + HCl = PCl5 + H2o
Answer:
H3PO4 + 5 HCl → PCl5 + 4 H2O
Explanation:
The given equation is
H3PO4 + HCl = PCl5 + H2O
The above chemical equation has one P atom on both the sides, hence phosphorus is balanced
There are 5 Cl on the RHS but only one Cl on the LHS. On balancing the chlorine, we get -
H3PO4 + 5HCl = PCl5 + H2O
Now, there are 8 hydrogen atom on the LHS but only two on the RHS. On balancing the hydrogen on both the sides, the new equation become
H3PO4 + 5HCl = PCl5 + 4H2O
Let us check for oxygen
Oxygen on LHS = 4 and oxygen on RHS = 4
Thus, the balanced equation is H3PO4 + 5HCl = PCl5 + 4H2O
200.0g of a 3.0% NaF solution, how much distilled water do we weigh out?
197g of distilled water
194g of distilled water
140g of distilled water
170g of distilled water
Answer:
194g of distilled water.
Explanation:
Hello there!
In this case, according to the given information for this problem, it turns out possible for us to use the given mass of the solution and the percent by mass of NaF to firstly calculate the grams of this solute as shown below:
[tex]\%m=\frac{m_{solute}}{m_{solution}} *100\%\\\\m_{solute}=\frac{\%m*m_{solution}}{100\%} \\\\m_{solute}=\frac{3.0\%*200.0g}{100\%} \\\\m_{solute}=6g[/tex]
And finally, since the mass of solution is calculated by adding mass of solute and mass of solvent we obtain the mass of water (solvent) as follows:
[tex]m_w=200g-6g=194g[/tex]
Therefore, the answer is 194g of distilled water
Regards!
The molar mass of water is 18.02 g/mol. A mass of 160.0 grams of water is equivalent to how many moles?
please show work!
Answer:
8.879 moles.
Explanation:
From the question given above, the following data were obtained:
Molar mass of water = 18.02 g/mol
Mass of water = 160.0 g
Mole of water =?
Mole is defined by the following equation:
Mole = mass / molar mass
With the above formula, we can obtain the number of mole present in 160 g of water. This can be obtained as follow:
Molar mass of water = 18.02 g/mol
Mass of water = 160.0 g
Mole of water =?
Mole = mass / molar mass
Mole of water = 160 / 18.02
Mole of water = 8.879 moles.
Therefore, 160 g of water contains 8.879 moles.
Use the equations below to calculate the enthalpy of formation for propane gas, C3H8, from its elements, hydrogen gas and solid carbon. Please hurry!!
Answer: I got -4542.9kg/mol
Explanation:
Using the enthalpy relation, the enthalpy of formation of propane gas in the given equation is 4542.9 kJ/mol
[tex] △H_{f} = Product [/tex]Using the enthalpy value of [tex] CO_{2} [/tex] and[tex] H_{2}0[/tex] given :
Product = [tex] 3CO_{2} + 4H_{2}0[/tex] Product = 3(-393.5) + 4(-285.8) = - 2323.70Reactant = [tex] C_{3}H_{8} + 5H_{2}0[/tex] Water, H20 has △H = 0Reactant = [tex] C_{3}H_{8} + 0[/tex]
Enthalpy of formation = product - Reactant
2219.2 = -2323.70 - (propane + 0)
2219.2 = - 2323.70 - propane
Propane = - 2323.70 - 2219.2
[tex] C_{3}H_{8} = - 4542.9 [/tex]
Therefore, the entalphy of formation of propane gas is - 4542.9 kJ/mol.
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Please don't give me a wedsite
Why is a wire used to connect the electrodes in an electrochemical cell?
O A. To provide the metal that is the oxidizing agent
B. To prevent the flow of protons from electrodes
C. So ions can flow from one electrode to another
D. So electrons can flow from one electrode to another
Answer:
D. So electrons can flow from one electrode to another
Explanation:
An electrochemical cell is any cell in which electricity is produced by reason of a chemical change.
An electrochemical cell consists of two electrodes, these two electrodes are connected using a wire.
Usually, electrons flow from one electrode to another via this wire thereby enabling the electrochemical processes of oxidation and reduction in the cell to proceed effectively.
If the fan and power source are not connected to anything else, the amount of electrical energy is the same as the amount of mechanical energy. What is this rule known as?
1. transference of energy
2. conversion of energy
3. adaptation of energy
4. conservation of energy
Answer:
not B
Explanation:
my friend got it wrong
130 cm of a gas at 20°C exerts a pressure of
750 mm Hg. Calculate its pressure if its volume
is increased to 150 cm3 at 35 °C.
Answer: The pressure is 1137.5 mm Hg its pressure if its volume is increased to 150 [tex]cm^{3}[/tex] at 35 °C
Explanation:
Given: [tex]P_{1}[/tex] = 750 mm Hg, [tex]V_{1} = 130 cm^{3}[/tex], [tex]T_{1} = 20^{o}C[/tex]
[tex]P_{2}[/tex] = ?, [tex]V_{2} = 150 cm^{3}[/tex], [tex]T_{2} = 35^{o}C[/tex]
Formula used to calculate the new pressure is as follows.
[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}[/tex]
Substitute the values into above formula as follows.
[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}\\\frac{750 mm Hg \times 130 cm^{3}}{20^{o}C} = \frac{P_{2} \times 150 cm^{3}}{35^{o}C}\\P_{2} = 1137.5 mm Hg[/tex]
Thus, we can conclude that the pressure is 1137.5 mm Hg its pressure if its volume is increased to 150 [tex]cm^{3}[/tex] at 35 °C.
What frequency corresponds to an absorption line at 460 nm?
A. 1.53 x 1014 Hz
B. 6.88 x 1014 Hz
C. 6.52 x 1014 Hz
D. 4.32 x 1014 Hz
Answer:
C. 6.52 x 10^14 Hz
Explanation:
hope this helps
A simple way to look at kinetic energy is
A. Violent motion
B. The energy involved when you sit down
C. The energy when you move
D. The energy in a candy bar
E. The high energy, not known to be essential
Answer:
c I do believe good luck with the answer
12. An electrolysis reaction is
A. hydrophobic.
B. spontaneous.
C. exothermic.
D. non-spontaneous.
Answer: D.) non-spontaneous.
Explanation:
How many atoms are in 6.7 moles of iron?
Answer:
4.034x10^24 atoms
Explanation:
6.7 x 6.023x10^23 = 4.034x10^24 atoms
4.0348348050000003e+24
:|
For each of the following compounds, decide whether the compound's solubility in aqueous solution changes with pH. If the solubility does change, pick the pH at which you'd expect the highest solubility. You'll find Ksp data in the ALEKS Data tab. compound Does solubility change with pH
Answer: Hello attached below is the complete question and using data from ALEKS data tab
answer:
PbCl₂ : Yes , PH = 3
CaC0₃ : Yes, PH = 3
AgCn : Yes , PH = 3 .
Explanation:
For PbCl₂
PbCl₂ solubility will change ( decrease ) with increase in PH, and the PH at which PbCl₂ will be most soluble is at PH = 3
For CaC0₃
Addition of -ions which increases the PH level will cause a decrease in the solubility of CaC0₃ hence the PH at which it will be most soluble in an aqueous solution is PH = 3
For AgCn
Increase in the PH level there would be a decrease in the solubility of AgCn hence the PH at which AgCn is most soluble ( highest solubility ) = 3
The ability of a solute to be able to dissolve is called solubility. Yes, at pH 3, the solubility of lead chloride, calcium carbonate, and silver cyanide.
What is solubility?The ability of the solute to get dissolved in a solvent to form a saturated solution is called solubility.
For lead chloride, the solubility will decrease as the pH will increase and is most soluble at a pH of 3.
For calcium carbonate, the addition of ions increases the pH will result in a decreased solubility, and will be most soluble at pH 3.
For silver cyanide increased pH decreases the solubility and is most soluble at a pH of three.
Therefore, solubility decrease with an increase in pH due to the concentration factor.
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How many moles are in 3.87 x 10 ^24 molecules of carbon?
Answer:
1 mole contains 6.02⋅1023 particles
Explanation:
Explanation:
X×6.02⋅1023=3.75⋅1024→
X=3.75⋅10246.02⋅1023=0.623⋅101=6.23 moles
Why would a doctor most likely restrict a patient’s contact with other people while the patient receives internal radiation?
A. The patient’s stress and anxiety would be eliminated.
B. High levels of radiation can diffuse through the patient’s skin.
C. Social contact would increase the effect of the radiation treatment.
D. Radioactive material can leave the patient’s body through saliva, sweat, and urine.
Answer:
D.......................
What is the oxidation state of nitrogen in Nz?
Answer:
the oxidation state of nitrogen is +5
Which two statements describe organ systems working together to bring
oxygen to cells?
O A. Blood vessels carry oxygen from the lungs to the heart.
B. Cells use oxygen to turn nutrients from food into energy.
C. The lungs allow oxygen from the air to enter the blood.
D. The brain monitors the level of oxygen in arteries.
Answer: A and C are the right answer.
Explanation:
What type of chemical reaction is represented by this balanced equation? S8(s)+802(g)-->8SO2(g)
Answer: I think it could be Decomposition
Explanation: I think is composition because decomposition starts by being together and ends up as two
Information normally shown as a continuous wave is analog or digital. Examples include music cds and smartphones is it analog or digital. Takes up a lot of space and degrades over time is it analog or digital. Examples include dimmer light switches and cameras that use film is it analog or digital. Purer data is more accurate and has more details is it analog or digital. Please help
Answer:
Music CDs and smartphones are digital.
Explanation:
Music CDs and smartphones are digital. Analogue takes up a lot of space and degrades with the [passage of time while on the other hand, digital takes less space and degrades in large piece of time. Dimmer light switches and cameras that use film is it analog not digital. The major difference between both signals is that the analog signals have continuous electronic signals, while digital signals have non-continuous electronic signals.
Hl Weakly dissociates in water according to the chemical equation below. H20+ Hl <-> H3O^+ + l- What is a conjugate acid-base pair in this reaction?
Answer:
https://www.clutchprep.com/chemistry/practice-problems/70217/hi-aq-h2o-l-h3o-aq-i-aq-identify-each-as-either-a-bronsted-lowry-acid-bronsted-l
Explanation:
https://www.clutchprep.com/chemistry/practice-problems/70217/hi-aq-h2o-l-h3o-aq-i-aq-identify-each-as-either-a-bronsted-lowry-acid-bronsted-l
A student reads a barometer in the laboratory and finds the prevailing atmospheric pressure to be 736 mmHg. Express this pressure in torr and in atmospheres.
Answer:
736 mmHg = 0.97 atm (Approx.)
736 mmHg = 736 Torr
Explanation:
Given barometer in the laboratory atmospheric pressure data:
Atmospheric pressure in mmHg = 736 mmHg
Find:
Change given data into Torr
Change given data in atm (atmospheric pressure)
Computation:
We know that;
1 atm = 760 mmHg
So,
736 mmHg = 736 / 760
736 mmHg = 0.97 atm (Approx.)
We know that;
760 mmHg = 760 Torr
So,
736 mmHg = 736 Torr
Explain what matter is, and all of the states it can have.
Answer:
matter is anything that occupies space
states of matter : solid,liquid, gas,plasma
Answer:
matter can be anything, tables chairs, literally anything. it has volume and takes up space.
Explanation:
Solids, liquids, gases, plasmas, and Bose-Einstein condensates (BEC)
By what factor does [OH- ] change when the pH increases by 1.7?
When a conditions could exist: liquid is in dynamic equilibrium with its vapor at a given temperature, the following
(I) There is no transfer of molecules between liquid and vapor
(II) The vapor pressure has a unique value
(III) The opposing processes, (liquid to vapor) and (vapor to liquid), proceed at equal rates
(IV) The concentration of vapor is dependent on time
Which of the above choices are applicable?
a. I
b. II and III
c. I, II, and III
d. II and IV
e. none of these combination
In dynamic equilibrium conditions, the vapor pressure is unique, and the rate of vaporization and condensation are at equal rates. Thus, option b is accurate.
What is dynamic equilibrium?A dynamic equilibrium is a reaction state where the rate of the forward and the backward reaction are equal. In the above case, the vapourization and the condensation will occur simultaneously at the same rate.
The vapor pressure of the liquid to gas and vice versa has a distinctive value as the temperatures are different making the pressure change directly.
Therefore, option b. II and III are the correct options.
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Which substance is the best oxidizing agent?
A. NaOH
B. H2O
C. Xe
D. HCI
E. O3
Answer:
the answer is A.
Explanation:
Elemental fluorine, for example, is the strongest common oxidizing agent.
How much water, in grams, can be made from 1.84 × 1024 hydrogen molecules?
Answer:
55.0g water can be made
Explanation:
To solve this question, we must convert the molecules of H2 to moles using Avogadro's constant. With the moles, and the reaction:
H2 + 1/2O2 → H2O
We can find the moles of H2O = Moles H2 and its mass of using molar mass of water -H2O = 18.01g/mol-
Moles H2 = Moles H2O:
1.84x10²⁴ molecules * (1mol / 6.022x10²³ molecules) = 3.055 moles H2O
Mass:
3.055 moles H2O * (18.01g / mol) = 55.0g water can be made
A sample of gas at 90 degrees Celsius occupies 15.5 L. This gas is heated to occupy a new volume of 20.3L. What is the new temperature of the gas?
Answer:
202 °C
Explanation:
From the question given above, the following data were obtained:
Initial temperature (T₁) = 90 °C
Initial volume (V₁) = 15.5 L
Final volume (V₂) = 20.3 L
Final temperature (T₂) =?
Next, we shall convert 90 °C to Kelvin temperature. This is illustrated below:
T(K) = T(°C) + 273
Initial temperature (T₁) = 90 °C
Initial temperature (T₁) = 90 °C + 273
Initial temperature (T₁) = 363 K
Next, we shall determine the final temperature.
Initial temperature (T₁) = 363 K
Initial volume (V₁) = 15.5 L
Final volume (V₂) = 20.3 L
Final temperature (T₂) =?
V₁ / T₁ = V₂ / T₂
15.5 / 363 = 20.3 / T₂
Cross multiply
15.5 × T₂ = 363 × 20.3
15.5 × T₂ = 7368.9
Divide both side by 15.5
T₂ = 7368.9 / 15.5
T₂ ≈ 475 K
Finally, we shall convert 475 K to celsius temperature. This is illustrated below:
T(°C) = T(K) – 273
T₂ = 475 – 273
T₂ = 202 °C
Thus, the new temperature of the gas is 202 °C