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emmasim [6.3K]
4 years ago
9

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]4 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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Roberto makes a graphic organizer to compare fusion nuclear reactions and fission nuclear reactions. A venn diagram with 2 inter
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Answer:

The second one

Explanation:

The second one is joining so it is the one which belongs to X, first one belongs to Z

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Wave A has a longer wavelength than wave B, but their amplitudes are the same. Which carries more energy?
dangina [55]
The answer to this question would be B.
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A sound wave has a frequency of 425 Hz. What is the period of this wave?
Serhud [2]
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3 years ago
A 40-kg rock is dropped from an elevation of 10 m. What is the velocity of the rock when it is 5-m from the ground?
ivolga24 [154]

Answer:

Explanation:

Given

mass of rock m=40\ kg

Elevation of Rock h=10\ m

Distance traveled by rock with time

h=ut+\frac{1}{2}at^2

where, u=initial velocity

t=time

a=acceleration

here initial velocity is zero

when rock is 5 m from ground then it has traveled a distance of 5 m from top because total height is 10 m

5=0\times t+\frac{1}{2}(9.8)(t^2)

t^2=\frac{10}{9.8}

t=1.004\approx 1\ s

velocity at this time

v=u+at

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6 0
3 years ago
If Justin races his Chevy S-10 down highway 37 north for 2,560 meters in 60 seconds, what is
Harrizon [31]

Answer:

A.) 42.7 m/s

B.) 0.33 m/s^2

C.) 90 kg

Explanation:

A.) If Justin races his Chevy S-10 down highway 37 north for 2,560 meters in 60 seconds, what is his velocity? 

Velocity = displacement/time

Velocity = 2560/60

Velocity = 42.67 m/s

B.) The Chevy S-10 started rounding at 10 meters per hour. What is the acceleration at 30 seconds on the highway?

Acceleration = velocity/time

Acceleration = 10/30

Acceleration = 0.33 m/s^2

C.) The S-10 has a force of 30 N. What is the mass of the car?

Force = mass × acceleration

30 = mass × 0.33

Mass = 30/ 0.33

Mass = 90 kg

8 0
3 years ago
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