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
joja [24]
3 years ago
13

How much heat energy, in kilojoules, is required to convert 53.0 g of ice at −18.0 ∘C to water at 25.0 ∘C ? Express your answer

to three significant figures and include the appropriate units.
Chemistry
1 answer:
ANTONII [103]3 years ago
8 0

Answer:

25.2 kJ of heat energy is required to convert 53.0 g of ice at −18.0 ∘C to water at 25.0 ∘C

Explanation:

Data: mass of ice = m = 53.0 g

         Temperature of ice = T1 = -18.0 ∘C

         Temperature of water = T2 = 25.0 ∘C

          Change in Temperature = ΔT : T2-T1                                          

           Specific heat of ice = c(i) = 2.09 J/g . ∘C

          Specific heat of water = c(w) = 4.18 J/g . ∘C

          Enthalpy of fusion of water (when convert from ice to water) = ΔH(f) : 334 J/g

          Enthalpy of vapourization of water (when convert from water to gas) = ΔH(v) :2250 J/g

          Total heat required = q = ?

Solution:        Heat required to melt the ice

                      T1 = -18 ∘C

                      T2 = 0 ∘C

                      Q1 = m x c(i) x ΔT

                      Q1 = 53.0 x 2.09 x (0-(-18))

                      Q1 = 53.0 x 2.09 x 18

                      Q1 = 1993.86 J is required by ice to reach to its

                      melting point.

                      <u>Heat required to convert the ice into water</u>

                      Q2 = ΔH(f) x m

                      Q2 = 334 x 53.0 = 17702 J is required by ice to  

                      convert into water.

                      <u> Heat required by water to reach at 25 ∘C</u>

                       T1 = 0 ∘C

                       T2 = 25 ∘C

                       Q3 = m x c(w) x ΔT

                       Q3 = 53.0 x 4.18 x (25-0)

                       Q3 = 5538.5 J is required by water to reach at  

                       25∘C .

                       <u>Total heat required by 53.0 g of ice at −18.0 ∘C  </u>

                        <u>to water at </u>

                        <u>25.0 ∘C</u>

                        q = Q1 + Q2 + Q3

                        q = 1993.86 J + 17702 J + 5538.5 J

                        q = 25234.36 J is the total heat required 53.0 g  

                        of ice at −18.0 ∘C to water at 25.0 ∘C.

                        <u>Conversion from Joule (J) to Kilojoule (kJ)</u>

                          1000 J =  1 kJ

                          q = 25234.36 J/1000

                          q = 25.23436 kJ

                           <u>Conversion of heat in kJ to three significant   </u>

                           <u>figures</u>

                           q = 25.2 kJ

You might be interested in
What is the name of John Daltons theory
Rashid [163]

Answer:

It is called the atomic theory I believe.

Explanation:

5 0
3 years ago
What is the pOH of a 0.150 M solution of potassium nitrite? (Ka HNO2 = 4.5 x 10−4 )
yanalaym [24]

Answer:

11.9 is the pOH of a 0.150 M solution of potassium nitrite.

Explanation:

Solution :  Given,

Concentration (c) = 0.150 M

Acid dissociation constant = k_a=4.5\times 10^{-4}

The equilibrium reaction for dissociation of HNO_2 (weak acid) is,

                           HNO_2+H_2O\rightleftharpoons NO_2^-+H_3O^+

initially conc.         c                       0         0

At eqm.              c(1-\alpha)                c\alpha        c\alpha

First we have to calculate the concentration of value of dissociation constant (\alpha ).

Formula used :

k_a=\frac{(c\alpha)(c\alpha)}{c(1-\alpha)}

Now put all the given values in this formula ,we get the value of dissociation constant (\alpha ).

4.5\times 10^{-4}=\frac{(0.150\alpha)(0.150\alpha)}{0.150(1-\alpha)}

4.5\times 10^{-4} - 4.5\times 10^{-4}\alpha =0.150\alpha ^2

0.150\alpha ^2+4.5\times 10^{-4}\alpha-4.5\times 10^{-4}=0

By solving the terms, we get

\alpha=0.0533

No we have to calculate the concentration of hydronium ion or hydrogen ion.

[H^+]=c\alpha=0.150\times 0.0533=0.007995 M

Now we have to calculate the pH.

pH=-\log [H^+]

pH=-\log (0.007995 M)

pH=2.097\approx 2.1

pH + pOH = 14

pOH =14 -2.1 = 11.9

Therefore, the pOH of the solution is 11.9

4 0
3 years ago
How would you know if a precipitate was formed without performing the chemical reaction
Goshia [24]
Hey there

Thats easy

Precipitation occurs when cations and anions in aqueous solution combine to form an insoluble ionic compound called precipitation. So, you can refer to a solubility chart or draw polar/nonpolar lewis structures, that might be helpful.
Remember water is polar so polar molecules will dissolve in water 
4 0
3 years ago
The electrons in a bond between two iodine atoms (I2) are shared
lesya [120]

Answer:

Your answer

Explanation:

The answer is

d.

7 0
2 years ago
Read 2 more answers
What letter on the model titration curve corresponds to the point where ph equals the numerical value of pka for hpr? what speci
irakobra [83]

Letter C on the model titration curve corresponds to the point where pH equals the numerical value of pKa for HPr

<h3>What is a titration curve?</h3>

A titration curve is a graph of the pH of a solution against increasing volumes of an acid or a base that is added to the solution.

The pH of a solution is the negative logarithm to base ten of the hydrogen ion concentration and is a measure of the acidity or alkalinity of the solution.

The pKa is the acid dissociation constant of an acid solution.

In a titration of a strong acid and strong base, the pH at equivalence point is equal to the pKa of the acid.

The equivalence point is the point when equal moles of acids and base has reacted.

In the given titration curve, pH = pKa at point C.

In conclusion, for a titration curve of strong acid and base, at equivalence point, pH is equal to pKa of acid.

Learn more about equivalence point at: brainly.com/question/23502649

#SPJ1

4 0
2 years ago
Other questions:
  • 365g MnSiO3 = ___ mol
    8·1 answer
  • Which planet is sometimes called Uranus’s twin? Saturn Pluto Jupiter Neptune
    10·2 answers
  • A reaction mechanism is defined as the sequence of reaction steps that define the pathway from reactants to products. Each step
    13·1 answer
  • 42. What is the valency of carbon in CH3-CH3, CH2=CH2 and HC=CH​
    7·1 answer
  • Temperature, density, and pressure ______________ (increases, decreases) as depth ____________ (increases, decreases).
    10·2 answers
  • I NEED HELP ASAP!!! PLEASE!!!
    6·2 answers
  • Two processes are described below:
    10·2 answers
  • Match the characteristics of each of the substance to their category
    14·1 answer
  • water and ammonia are polar. The hydrogen atoms in each have a slight positive charge. What does that tell you about the oxygen
    8·1 answer
  • Does ccl4 has resonance structures
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!