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3 years ago

Is the reduction of copper from copper(ii) oxide by carbon exothermic or endothermic? what is the sign of the energy change?

Physics

1 answer:

Sloan [31]3 years ago

8 0

Answer;

-Exothermic reaction;

-The sign of the energy change is negative (-)

Explanation;

2CuO(s) + C(s) --> 2Cu(s) + CO2(g)

ΔH = ΣΔHf(products) - ΣΔHf(reactants)

ΔH = -393.5kJ - 2(-155.2kJ) = -83.1 kJ

The reaction is exothermic.

-An exothermic process or reaction releases heat, causing the temperature of the immediate surroundings to rise. An endothermic process absorbs heat and cools the surroundings.

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Two coils of wire are placed close together. Initially, a current of 3.04 A exists in one of the coils, but there is no current

Alchen [17]

Answer:

$M=0.0247H$

Explanation:

Given data

$V_{voltage}=4.29V\\I_{current}=3.04A\\t_{time}=1.75*10^{-2}s$

To find

Mutual inductance of the two-coil system

Solution

The mutual inductance given as:

M= (-VΔt)/ΔI

Substitute the given values

$M=-\frac{4.29V*1.75*10^{-2}s}{(0-3.04A)}\\ M=0.0247H$

4 0

3 years ago

Add the vectors:

Anettt [7]

Vector 1 has components

$x_1=(10\,\mathrm m)\cos20^\circ\approx9.40\,\mathrm m$

$y_1=(10\,\mathrm m)\sin20^\circ\approx3.42\,\mathrm m$

and vector 2 has

$x_2=(10\,\mathrm m)\cos80^\circ\approx1.74\,\mathrm m$

$y_2=(10\,\mathrm m)\sin80^\circ\approx9.85\,\mathrm m$

Add these vectors to get the resultant, which has components

$x_{\rm total}\approx11.133\,\mathrm m$

$y_{\rm total}\approx13.268\,\mathrm m$

The magnitude of the resultant is

$\sqrt{{x_{\rm total}}^2+{y_{\rm total}}^2}\approx17.321\,\mathrm m$

with direction $\theta$ such that

$\tan\theta=\dfrac{y_{\rm total}}{x_{\rm total}}\implies\theta\approx50^\circ$

or about 50º N of E.

8 0

3 years ago

What TWO things affect the gravitational force acting on an object?

ohaa [14]

The strength of the gravitational forces between two masses depends on

-- the product of the masses,

-- the distance between their centers of mass.

3 0

3 years ago

Read 2 more answers

What is the relationship between a photons energy and its wavelength?

Elanso [62]

Answer:

The amount of energy is directly proportional to the photon's electromagnetic frequency and thus, equivalently, is inversely proportional to the wavelength. The higher the photon's frequency, the higher its energy. Equivalently, the longer the photon's wavelength, the lower its energy.

Explanation:

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3 years ago

Hoover Dam on the Colorado River is the highest dam in the United States at 221m, with a power output of 680 MW. The dam generat

DiKsa [7]

Answer:

The power in this flow is $9.56\times10^{8}\ W$