1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
emmasim [6.3K]
3 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]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.

You might be interested in
Which of the following will be the best condition for bread fermentation?
dezoksy [38]

Answer:

a. Wet, soft dough at 85 degrees Fahrenheit

Explanation:

Fermentation is an anaerobic process that transforms starches into simpler substances. The rising of dough is due to fermentation.

According to Harold McGee, 85°F (29°C) is the best temperature for fermenting bread dough. Temperatures below 85°F (29°C) take  much longer to ferment, and temperatures higher than that result into unpleasant flavors in the dough.

Wet, soft dough is usually more preferable because it produces a softer bread.

3 0
3 years ago
Make the following conversion. 120 mL = _____ cm³ 12.0 1200 120 1.20
omeli [17]
120 is your answer. 120 mL = 120 cm^3
7 0
3 years ago
Read 2 more answers
When responding to sound, the human eardrum vibrates about its equilibrium position. Suppose an eardrum is vibrating with an amp
Paraphin [41]

Answer:

796.18 Hz

Explanation:

Applying,

Maximum velocity = Amplitude×Angular velocity

Therefore,

V' = A(2πf)............... Equation 1

Where V' = maximum velocity of the eardrum, A = Amplitude of vibration of the eardrum, f = frequency of the eardrum vibration, π = pie

make f the subject of the equation

f = V'/2πA................ Equation 2

From the question,

Given: V' = 3.6×10⁻³ m/s, A' = 7.2×10⁻⁷ m,

Constant: 3.14.

Substitute these values into equation 2

f = 3.6×10⁻³/( 7.2×10⁻⁷×2×3.14)

f = 796.18 Hz

6 0
3 years ago
Explain why some of the tree get detached from a tree if we vigorously shake it's Branch.​
Rasek [7]

Answer:

When a tree is vigorously shaken, the branches of the tree come in motion but the leaves tend to continue in their state of rest due to inertia of rest. As a result of this, leaves get separated from the branches of the tree and hence fall down.

8 0
3 years ago
Read 2 more answers
Consider a situation where you are playing air hockey with a friend. The table shoots small streams of air upward to keep the pu
artcher [175]

When we hit the puck from tap the puck will move forward.

This is due to the impulse provided by us at the time of hit. Due to this impulse the puck will move forward and start moving in some direction.

As soon as puck move forward the force on it is zero as the weight of the puck is counterbalanced by the air stream force and there is no other force on it so puck will continue its motion till it will hit at some other point.

So here the motion of the puck will be uniform motion till it will collide with some other points.

So here the correct option will be given as

<em>moves with a constant speed until hitting the other end.</em>

5 0
3 years ago
Other questions:
  • The New Horizons probe flew past Pluto in July 2015. At the time, Pluto was about 32 AU from Earth. How long did it take for com
    14·1 answer
  • The relative hardness of a mineral can best be tested by
    7·1 answer
  • What are the three main ideas associated with Newton’s second law of motion? List these in your own words .
    6·1 answer
  • a car advertisement states that a certain car can accelerate from rest to 70km/h in 7 seconds. find the cars acceleration
    7·1 answer
  • A car of mass 1600 kg can just be lifted what is the least force that the electronicmagnet must use to lift the car ?
    15·1 answer
  • Use cylindrical coordinates. Evaluate E (x − y) dV, where E is the solid that lies between the cylinders x2 + y2 = 1 and x2 + y2
    6·1 answer
  • 1. The first thing to do in the event of brake failure is to a. use the parking brake to stop your carb. pump the brake pedal ra
    12·1 answer
  • A 300 kg car initially travels with a velocity of 20 m/s to the right. A net force F acts on the car for 5 s, which causes the v
    6·1 answer
  • How much energy is consumed by a 12 W night light left on for 10 hr?
    13·1 answer
  • Name THREE things that impact a collision.
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!