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
Stells [14]
3 years ago
11

A 20g piece of lead absorbs 566 joules of heat and its temperature changes from 35 oC to 195 oC. Calculate the specific heat.

Chemistry
1 answer:
Alja [10]3 years ago
8 0

Answer:

  • <u>Question 1: 0.2J/(gºC)</u>
  • <u>Question 2: 6,000J</u>
  • <u>Question 3: 300J</u>
  • <u>Question 4: 80g</u>
  • <u>Question 5: 74ºC</u>
  • <u>Question 6: 50g</u>

<u></u>

Explanation:

Question 1.<em> A 20g piece of lead absorbs 566 joules of heat and its temperature changes from 35º oC to 195º C. Calculate the specific heat.</em>

<em />

The thermal energy equation is:

  • Q = m × C × ΔT

<em />

Substitute and solve for C:

  • 566J = 20g × C × (195ºC - 35ºC)
  • C = 566J / (20g × 160ºC)
  • C = 0.177 J/(gºC) ≈ 0.2J/(gºC)

<em />

You must round to one significant figure because one factor has one significant figure).

<em />

<em />

Qustion 2.<em> 40g of water is heat at 40ºC and the temperature rise to 75ºC. What is the amount of heat needed for the temperature to rise? (specific heat of water is 4.184 J/gºC)</em>

<em />

Use the thermal energy equation again:

  • Q = m × C × ΔT

<em />

Substitute and compute:

  • Q = 40g × 4.184 J/gºC × (75ºC - 40ºC)
  • Q = 5,857.6J

Round to one significant figure: 6,000J

<em />

Question 3. <em>Graphite has a mass of 50g and a specific heat of 0.420 J/gºC. If graphite is cooled from 50ºC to 35ºC, how much energy was lost?</em>

  • Q = m × C × ΔT
  • Q = 50g × 0.420J/gºC × (35ºC - 50ºC)
  • Q = 315J

Round to one significant figure (because 50g has one significant figure)

  • Q = 300J

<em />

Question 4.<em> </em><em>Iron has a specific heat of 0.712 J/gºC. A piece of iron absorbs 3000J of energy and undergoes a temperature change totaling 50ºC, What is the mass of iron?</em>

<em />

  • Q = m × C × ΔT

Solve for m:

  • m = Q / (C × ΔT)

Substitute and compute:

  • m = 3,000J / (0.712J/gºC × 50ºC)
  • m = 84.26 g ≈ 80 g (rounded to one significant figure, because the factor 3,000J has one significant figure).

Question 5. <em>If 400g of an unknown solution at 70ºC loses 7500 J of heat, what is the final temperature of the unknown solution. The unknown solution has a specific heat of 4.184 J/gºC.</em>

<em />

  • Q = m × C × ΔT

<em />

Q is negative, since it is released.

Substitute and solve for T:

  • - 7,500J = 400g × 4.184J/gºC × (T - 70ºC)

  • T = - 7500J / 400g × 4.184J/gºC) + 70ºC

  • T = 74ºC

<em />

If you round to one significant figure you cannot tell the temperature difference, thus leave two significant figures.

<em />

Question 6. <em>How many grams of water would require 9500J of heat to raise the temperature from 50ºC to 100ºC</em>

  • Q = m × C × ΔT

Subsitute:

  • 9,500J = m × 4.184J/gºC × (100ºC - 50ºC)

Solve for m and compute:

  • m = 9,500J / (4.184J/gºC × 50ºC)

  • m = 45g

Since the temperatures indicate one singificant figure, the mass should be rounded to one significant figure:

  • m = 50g.
You might be interested in
In which of the following cases will the LEAST time be required to arrive at equilibrium? K below refers to the equilibrium cons
mylen [45]

Answer: Option (4) is the correct answer.

Explanation:

It is known that equilibrium constant is represented as follows for any general reaction.

                 A + B \rightarrow C + D

                   K = \frac{[C][D]}{[A][B]}

As equilibrium constant is directly proportional to the concentration of products so more is the value of equilibrium constant more will be the number of products formed.

As a result, more is the time taken by the reaction to reach towards equilibrium. Whereas smaller is the value of equilibrium constant more rapidly it will reach towards the equilibrium.

Thus, we can conclude that cases where K is a very small number will require the LEAST time to arrive at equilibrium.

8 0
3 years ago
Which process is exothermic?
valkas [14]
The exothermic process is a process or reaction that involves a release of energy from the system to its surroundings in various forms usually through heat, light, electricity or sound. In the four given choices, when melting a copper, you try to immerse the metal in  heaping coals of fire. The metal will absorb the thermal energy coming from the coal, thus, once you retrieve the metal back, light will be emitted from it as well as heat.

Therefore, the answer is B. MELTING OF COPPER
4 0
3 years ago
Read 2 more answers
I need an answer now please asap and you will me marked brainiest please it's missing I need it now.
ioda

Answer:

Where are the question's???

Explanation:

7 0
3 years ago
Which law states that at constant temperature the pressure of a given amount of gas is inversely proportional to the volume of t
Phantasy [73]
That law is known as Boyle's Law, "The volume of a given mass of a gas is inversely related to pressure when the temperature is constant"
8 0
3 years ago
Which mixtures could be separated using filtration? Check all that apply.
cestrela7 [59]

Answer:

smoky air

fresh river water

Explanation:

just did the assignment

5 0
3 years ago
Read 2 more answers
Other questions:
  • What volume of beaker contains exactly 2.23x10^-2 mol of nitrogen gas at STP?
    6·1 answer
  • What are the units for density
    5·1 answer
  • Water could be made to boil at 105 C instead of 100 C by ____. (1 point) adding a lot of energy to the water increasing the exte
    14·2 answers
  • Can anyone help me out literally lost and confused
    14·1 answer
  • Which substance can be broken down by a chemical change? antimony,carbon,water or sulfur
    7·1 answer
  • g Calculate the [OH-] from the results of your titrations. Explain your calculations2. Calculate the [Ca2+]. Explain your calcul
    15·1 answer
  • Both slicing a tomato and a chemical change such as burning toast cannot be reversed. However, why is slicing a tomato still con
    10·2 answers
  • A team of researchers is investigating a new carbon-rich molecule important to life. They find evidence for the presence of both
    15·1 answer
  • Looking at the web above, each letter represents a species of animal in an ecosystem food web. Which of the following is most li
    11·1 answer
  • Danny lowers the sails on his boat. He paddles upstream at 19 km/hr. The current is still running downstream at 15 km/hr. What i
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!