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
sineoko [7]
3 years ago
15

HELP me quickly PLEASE!!!!

Chemistry
1 answer:
Elina [12.6K]3 years ago
7 0

Answer:

Q1: 320 J.

Q2: The 150 g Al will reach a higher temperature.

Explanation:

<u><em>Q1:</em></u>

  • The amount of heat added to or released from a substance (Q) can be calculated from the relation:

<em>Q = m.c.ΔT.</em>

where, Q is the amount of heat added or released,

m is the mass of the substance (m = 40.0 g),

c is the specific heat of the substance (c = 0.5 J/g.°C, the value of c of the solid ethanol, ethanol be solid at the temperature change mentioned).

ΔT is the temperature difference (final T - initial T) (ΔT = − 136 °C − (− 120 °C) = − 16 °C.

∴ Q = m.c.ΔT = (40.0 g)(0.5 J/g.°C)(− 16 °C) = − 320 J.

The negative sign means that the heat is released.

<em>∴ The amount of heat is released when 40.0 g of ethanol cools from (−120 °C to −136 °C) = 320 J.</em>

<em>Q2:</em>

Explanation:

  • The amount of heat added to a substance (Q) can be calculated from the relation:

<em>Q = m.c.ΔT.</em>

where, Q is the amount of heat added,

m is the mass of the substance,

c is the specific heat of the substance,

ΔT is the temperature difference (final T - initial T).

Since, Q and c is constant, ΔT will depend only on the mass of the substance (m).

∵ ΔT is inversely proportional to the mass of the substance.

∴ The piece with the lowest mass (150.0 g) will reach a higher temperature than that of a higher mass (250.0 g).

<em>So, the right choice is: The 150 g Al will reach a higher temperature.</em>

<em></em>

You might be interested in
The factor 0.01 corresponds to which prefix? A) milli B) deci C) deka D) centi
BARSIC [14]
The answer is: D) centi
5 0
3 years ago
A 28.5 g piece of gold is heated and then allowed to cool. What is the change in temperature (°C) if the gold releases 0.106 kJ
Shkiper50 [21]

Considering the definition of calorimetry and sensible heat, the change in temperature if the gold releases 0.106 kJ of heat as it cools is 28.78°C.

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

Sensible heat is the amount of heat that a body absorbs or releases without any changes in its physical state (phase change). It is calculated by the expression:

Q = c× m× ΔT

where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.

In this case, you know:

  • Q= 0.106 kJ= 106 J (being 1 kJ=1000 J)
  • c= 25.4 \frac{J}{molC}
  • m= 28.5 g×\frac{1 mole}{196.967 g} = 0.145 moles (being 196.967 g/mole the molar mass of gold)
  • ΔT= ?

Replacing:

106 J= 25.4 \frac{J}{molC}× 0.145 moles× ΔT

Solving:

ΔT=\frac{106 J}{25.4\frac{J}{molC}x0.145 moles}

ΔT= 28.78 C

The change in temperature if the gold releases 0.106 kJ of heat as it cools is 28.78°C.

Learn more:

  • brainly.com/question/11586486?referrer=searchResults
  • brainly.com/question/24724338?referrer=searchResults
  • brainly.com/question/7435791
4 0
3 years ago
A solution is prepared from 8 grams of acetic acid (CH2CO2H) and 725 grams of water. What is the molarity of this solution?
Andrews [41]
Hello!

First, we can assume the density of water to be 1 g/mL, so the volume of water would be 725 mL. The density of Acetic Acid (Pure) is 1,05 g/mL so 8 grams would represent 7,61 mL

Now we can apply the following conversion factor to calculate the molarity of the solution, using the molar mass of Acetic Acid:

[CH_3CO_2H]=\frac{8 g_{CH_3CO_2H}  }{725 mL + 7,61 mL}* \frac{1000 mL}{1 L}* \frac{1 mol_{CH_3CO_2H} }{60,05 g_{CH_3CO_2H} }

[CH_3CO_2H]=0,1818 M

So, the concentration of acetic acid would be 0,1818 M

Have a nice day!
4 0
4 years ago
Read 2 more answers
Camphor is reduced to isoborneol by sodium borohydride in ethanol. The instructions for safe disposal of the chemical waste gene
Ronch [10]

Answer:

A) The reaction waste is still generating hydrogen gas that would get trapped in the container.

6 0
4 years ago
Read 2 more answers
9. How long will it take 120 grams of Strontium-90 to decay to 7.5 grams?<br>with steps pls​
ryzh [129]

Answer:

116 years

Explanation:

To solve this, we will use the half life equation;

A(t) = A_o(½)^(t/t_½)

Where;

A(t) is the amount of strontium left after t years;

A_o is the initial quantity of strontium that will undergo decay;

t_½ is the half-life of strontium

t is the time it will take to decay

We are given;

A(t) = 7.5 g

A_o = 120 g

From online values, half life of strontium-90 is 29 years. Thus, t_½ = 29

Thus;

7.5 = 120 × ½^(t/29)

Divide both sides by 120 to get;

7.5/120 = ½^(t/29)

0.0625 = ½^(t/29)

In 0.0625 = (t/29) In ½

-2.772589 = (t/29) × (-0.693147)

(t/29) = -2.772589/(-0.693147)

t/29 = 4

t = 29 × 4

t = 116 years

5 0
3 years ago
Other questions:
  • Why are numbers used in chemistry often expressed in scientific notation
    8·1 answer
  • What is the lowest &amp; highest quantity that can be measured?
    6·2 answers
  • What properties would you expect to be different for the two enantiomers of 2-pentanol?
    14·1 answer
  • How does a solute differ from a solvent?
    10·1 answer
  • Given:
    10·1 answer
  • ammonium nitrate, which is prepared from nitric acid, is used as a nitrogen fertilizer. determine the percent composition of amm
    7·1 answer
  • The boiling point of water (H2O) is 100 °C. Which of the following best predicts the boiling point of hydrogen sulfide (H2S)? (5
    8·1 answer
  • Which of the following is a characteristic of scientific investigation? Group of answer choices It is based on opinion. It is re
    10·1 answer
  • Fill in the Blank
    8·1 answer
  • What does it mean for a unit to be "derived"?
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!