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
nalin [4]
3 years ago
12

When a 12.8 g sample of KCL dissolves in 75.0 g of water in a calorimeter the temp. drops from 31 Celsius to 21.6 Celsius. Calcu

late deltaH for the process.
PLEASE EXPLAIN EVERY STEP.
Chemistry
1 answer:
Delicious77 [7]3 years ago
7 0

Answer:

Step 1: Calculate qsur (the surrounding is

usually the water)

qsur = ? J

m = 75.0 g water

c = 4.184 J/g

oC

ΔT = (Tfinal- Tinitial)= (21.6 – 31.0) = -9.4 oC

qsur = m · c · (ΔT)

qsur = (75.0g) (4.184 J/g

oC) (-9.4 oC)

qsur = - 2949.72 J

First, using the information we know that we

must solve for qsur, which is the water. We know

the mass for water, 75.0g, the specific heat of

the water, 4.184 j/g

o

c, and the change in

temperature, 21.6-31.0 = -9.4 oC. Plugging it

into the equation, we solve for qsur.

Step 2: Calculate qsys qsys = - (qsur)

qsys = - (- 2949.72 J)

qsys = + 2949.72

In this case, the qsur is negative, which means

that the water lost energy. Where did it go? It

went to the system. Thus, the energy of the

system is negative, opposite, the energy of the

surrounding.

Step 3: Calculate moles of the substance

that is the system

Given: 12.8 g KCl

Mol system = (g system given)

(molar mass of system)

Mol system = (12.8 g KCl)

(39.10g + 35.45g)

Mol system = 12.8 g KCl

74.55 g

Mol system = 0.172

Here, we solve for the mol in the system by

using the molar mass of the material in the

system.

Step 4: Calculate ΔH ΔH = q sys .

Mol system

ΔH= + 2949.72 J

0.172 mol

ΔH= +17179.81 J/mol or +1.72 x 104

J/mol

i hope this helps

You might be interested in
One of the primary functions of the digestive system is what
Nikitich [7]

Answer:

Breaks down and absorbs nutrients from the food and liquids you consume to use for important things like energy, growth and repairing cells.

8 0
3 years ago
If you were given two transparent liquids how would you determine which is pure and which is salt water
Tpy6a [65]
Based off the salt levels in each water.
8 0
3 years ago
Question 6: The Ideal Gas Law (7 points) a. What is the mathematical equation for the ideal gas law? Identify each variable and
azamat

The mathematical equation for the ideal gas law is PV = nRT.

<h3>What is an ideal gas equation?</h3>

The ideal gas law (PV = nRT) relates the macroscopic properties of ideal gases. An ideal gas is a gas in which the particles (a) do not attract or repel one another and (b) take up no space (have no volume).

(A)

PV = nRT

The ideal gas equation is formulated as: PV = nRT. In this equation, P refers to the pressure of the ideal gas, V is the volume of the ideal gas, n is the total amount of ideal gas that is measured in terms of moles, R is the universal gas constant, and T is the temperature.

(B)

Where the pressure - P, is in atmospheres (atm) the volume - V, is in liters (L) the moles -n, are in moles (m) and Temperature -T is in Kelvin (K) as in all gas law calculations.

(C)

A. Boyle's law

B. Charles's law

C. Avogadro's law

D. Dalton's law

____ - P_1V_1 = P_2 V_2

____ \frac{V}{T} = k

____ \frac{V_1}{T_1} = \frac{V_2}{T_2}

____ V = kn

____ PV = k

____- P total = P_1 + P_2 + P_3 + ...

<u>Boyle's</u><u> law</u> - P_1V_1 = P_2 V_2

<u>Charles's</u><u> law</u> - \frac{V}{T} = K

<u>Charles's law</u> - \frac{V_1}{T_1} = \frac{V_2}{T_2}

<u>Avogadro's law</u>- V = kn

<u>Boyle's law</u> - PV = k

<u>Dalton's law</u><u> </u>- P total = P_1 + P_2 + P_3 + ...

Learn more about the  ideal gas law here:

brainly.com/question/21353806

#SPJ1

6 0
2 years ago
The anion of which element has a –1 charge?
vovangra [49]
An anion is a negatively charged ion. An element can become an anion if it takes an extra electron such that it has one more electron than protons.
Atoms would preferentially taken an extra electron so that it can have a full octet and be more stable.

\sf Cl^-, Br^-, F^- are some of the few elements that would have a -1 charge.
6 0
2 years ago
What energy conversion in your body enables you to get out of bed in the morning
Vadim26 [7]
<span> The thermal </span>energy<span> is being </span>converted<span> to light </span>energy,<span> you are using electrical </span>energy<span>. </span>Your body<span> relies on the chemical </span><span>energy</span>
5 0
3 years ago
Other questions:
  • A proton is also known as this ion?
    7·1 answer
  • How many moles are in 9.25 x 10^58 atoms of copper
    7·1 answer
  • What is the charge for all elements in group 1A
    7·1 answer
  • How many moles of Al are needed to react completely with 1.2 moles of Fe0
    15·1 answer
  • Covalent bonds can occur where atoms share one or more pairs of electrons. Which of the following would form a double covalent b
    13·1 answer
  • Which of these waves would have the greatest amount of energy?
    9·2 answers
  • Question 10
    13·1 answer
  • Will GIVE BRAINLIST IF YOU ANSWER CORRECTLY Identity the type of reaction and balance the equation, including the states of matt
    5·1 answer
  • Which best describes why animals need the energy in food?
    12·2 answers
  • At what point on the roller coaster do the riders have the greatest amount of potential energy?
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!