All categories

8 days ago

What is the surprising thing that happens in a superconductor?

1 answer:

8 0

Generally, the electrical resistance of nearly all materials declines when they are subjected to lower temperatures. As they cool down further, this resistance continues to decrease. However, for some unique materials known as 'superconductors', an extraordinary phenomenon occurs: when their temperature decreases to a certain threshold, their resistance vanishes entirely, reaching absolute zero rather than just a negligible figure. In practical terms, if you initiate a current in a superconducting wire and complete the circuit by connecting the wire ends, that current can circulate indefinitely, maintaining its flow without diminishing for extended periods, provided the wire remains sufficiently chilled. This absence of resistance is key for various applications. For instance, numerous CT and MRI scanning devices depend on robust electromagnets, which consist of coils made from superconducting wires, kept in liquid helium. While this setup may sound intricate and costly, it's actually more practical and economical than using conventional electromagnets with copper wire and the substantial power supplies required for their operation. Additionally, wire resistance leads to energy loss when current moves through it. Energy dissipates along the lengthy cables from power plants to homes, resulting in unusable energy that electric companies cannot sell. Concepts are being introduced to create superconducting cables that transport electricity efficiently from power plants to consumers. These cables would be designed as hollow tubes insulated to maintain low temperatures with liquid helium or hydrogen inside, thus eliminating energy loss during transmission. Even though this approach could involve complexity and cost, the anticipated benefits, in terms of energy efficiency, outweigh the losses currently incurred with standard cables.

You might be interested in

For each reaction, identify the element that gets reduced and the element that gets oxidized. 2AgCl+Zn⟶2Ag+ZnCl2 Identify the el

KiRa [2857]

Answer:

Explanation:

The oxidation state corresponds to the charge of each atomic ion. An increase indicates oxidation of the element while a decrease reflects reduction of the element.

2AgCl+Zn⟶2Ag+ZnCl2

Zinc undergoes oxidation, while Ag experiences reduction.

Ag⁺ changes to Ag (oxidation state decreases), thus Ag is reduced.

Zn alters to Zn⁺² (oxidation state increases), hence Zn is oxidized.

4NH₃+3O₂⟶2N₂+6H₂O

The oxidation state of nitrogen in ammonia is -3

whereas it is zero in elemental nitrogen.

An increase in the oxidation state indicates nitrogen is oxidized.

The oxidation state of oxygen is zero when in molecular oxygen and -2 when in water. Therefore, the oxidation state decreases, indicating oxidation is reduced.

Fe₂O₃+2Al⟶Al₂O₃+2Fe

The oxidation state of Fe in Fe₂O₃ is +3, switching to zero in Fe, so iron is reduced.

Aluminum's oxidation state is zero in Al, rising to +3 in Al₂O₃, indicating it is oxidized.

7 0

13 days ago

At –45oC, 71 g of fluorine gas take up 6843 mL of space. What is the pressure of the gas, in kPa?

KiRa [2857]

The quantity of fluorine in moles is calculated as 71/19 = 3.74
We also know that at standard temperature and pressure (273 K and 101.3 kPa), one mole of gas occupies 22.4 liters
So, the volume for 3.74 moles at S.T.P is: 3.74 x 22.4
This results in a volume of 83.776 L, which is equivalent to 83,776 mL

Next, applying Boyle's law, which states that for a fixed amount of gas,
PV = constant

We set up the equation P x 6843 = 101.3 x 83776
Solving for P gives us 1,240 kPa

4 0

20 days ago

Los automóviles actuales tienen “parachoques de 5 mi/h (8 km/h)” diseñados para comprimirse y rebotar elásticamente sin ningún d

KiRa [2857]

Response: k = 23045 N/m

Clarification:

To determine the spring constant, one must consider the maximum elastic potential energy that the spring can withstand. The kinetic energy of the vehicle should equal at minimum the elastic potential energy of the spring when it is fully compressed. Hence, we express it as:

$K=U\\\\\frac{1}{2}Mv^2=\frac{1}{2}kx^2$ (1)

M: mass of the vehicle = 1050 kg

k: spring constant =?

v: car speed = 8 km/h

x: maximum spring compression = 1.5 cm = 0.015m

You need to resolve equation (1) for k. Beforehand, convert the speed v to meters per second:

$v=8\frac{km}{h}*\frac{1000m}{1km}*\frac{1h}{3600s}=2.222\frac{m}{s}$

$k=\frac{Mv^2}{x^2}=\frac{(1050kg)(2.222m/s)^2}{(0.015m)^2}=23045\frac{N}{m}$

The spring constant calculates to 23045 N/m

3 0

16 days ago

Ibuprofen, a headache remedy, contains 75.69% C, 8.80% H, and 15.51% O by mass and has a molar mass of 206 g/mol. Express your a

castortr0y [2913]

Answer:

A) The molecular formula for ibuprofen is $C_{13}H_{18}O_2$

B) The molecular formula for Cadaverine is $C_{5}H_{14}N_2$

C) The molecular formula for Epinephrine is $C_9H_{13}O_3N_1$

Explanation:

Element percentage in a compound:

$\frac{\text{Number of atoms of element}\times \text{Atomic mass of element}}{\text{molecular mass of element}}\times 100$

A) The composition of ibuprofen, used for headaches, consists of 75.69% carbon, 8.80% hydrogen, and 15.51% oxygen by weight.

Ibuprofen has a molar mass of 206 g/mol.

The proposed molecular formula for ibuprofen is = $C_xH_yO_z$

Count of carbon atoms in one ibuprofen molecule;

$75.69\%=\frac{x\times 12 g/mol}{206 g/mol}\times 100$

$x=\frac{75.69\times 206 g/mol}{100\times 12 g/mol}=12.99\approx 13$

Count of hydrogen atoms in one ibuprofen molecule;

$8.80\%=\frac{y\times 1 g/mol}{206 g/mol}\times 100$

$y=\frac{8.80\times 206 g/mol}{100\times 1 g/mol}=18.12\approx 18$

Count of oxygen atoms in one ibuprofen molecule;

$15.51\%=\frac{z\times 16 g/mol}{206 g/mol}\times 100$

$z=\frac{15.51\times 206 g/mol}{100\times 16 g/mol}=1.99\approx 2$

Molecular formula for ibuprofen:

= $C_xH_yO_z= C_{13}H_{18}O_2$

B) Cadaverine consists of 58.55% carbon, 13.81% hydrogen, and 27.40% nitrogen by weight

Cadaverine has a molar mass of 102.2 g/mol.

The proposed molecular formula for Cadaverine is = $C_xH_yN_z$

Count of carbon atoms in one Cadaverine molecule;

$58.55\%=\frac{x\times 12 g/mol}{102.2 g/mol}\times 100$

$x=\frac{58.55\times 102.2 g/mol}{100\times 12 g/mol}=4.98\approx 5$

Count of hydrogen atoms in one Cadaverine molecule;

$13.81\%=\frac{y\times 1 g/mol}{102.2 g/mol}\times 100$

$y=\frac{13.81\times 102.2 g/mol}{100\times 1 g/mol}=14.11\approx 14$

Count of nitrogen atoms in one Cadaverine molecule;

$27.40\%=\frac{z\times 14 g/mol}{102.2 g/mol}\times 100$

$z=\frac{27.40\times 102.2 g/mol}{100\times 14 g/mol}=2.00\approx 2$

Molecular formula for Cadaverine:

= $C_xH_yN_z= C_{5}H_{14}N_2$

C) Epinephrine includes 59.0% carbon, 7.1% hydrogen, 26.2% oxygen, and 7.7% nitrogen by weight

Epinephrine has a molar mass of 180 g/mol.

The proposed molecular formula for Epinephrine is = $C_xH_yO_zN_w$

Count of carbon atoms in one Epinephrine molecule;

$59.0\%=\frac{x\times 12 g/mol}{180 g/mol}\times 100$

$x=\frac{59.0\times 180 g/mol}{100\times 12 g/mol}=8.85\approx 9$

Count of hydrogen atoms in one Epinephrine molecule;

$7.1\%=\frac{y\times 1 g/mol}{180 g/mol}\times 100$

$y=\frac{7.1\times 180 g/mol}{100\times 1 g/mol}=12.78\approx 13$

Count of oxygen atoms in one Epinephrine molecule;

$26.2\%=\frac{z\times 16 g/mol}{180 g/mol}\times 100$

$z=\frac{26.2\times 180 g/mol}{100\times 16 g/mol}=2.94\approx 3$

Count of nitrogen atoms in one Epinephrine molecule;

$7.7\%=\frac{w\times 14 g/mol}{180 g/mol}\times 100$

$w=\frac{7.7\times 180 g/mol}{100\times 14 g/mol}=0.99\approx 1$

Molecular formula for Epinephrine:

= $C_xH_yO_zN_w= C_9H_{13}O_3N_1$

7 0

1 month ago

A compound with the molecular formula C10H10O4 produces a 1H NMR spectrum that exhibits only two signals, both singlets. One sig

Alekssandra [2891]

The accompanying illustration depicts the structure of dimethyl terephthalate. Explanation: Dimethyl terephthalate, whose chemical formula is C6H4 (COOCH3) 2, is a diester derived from terephthalic acid and methanol. It appears as a white solid. Another method of syntheses involves p-xylene and methanol, characterized by an oxidation process followed by esterification.

8 0

21 day ago