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
Varvara68 [4.7K]
2 years ago
15

140 g of KCl is dissolved in 600 mL of water. What is the molarity?

Chemistry
1 answer:
FromTheMoon [43]2 years ago
7 0

Answer:

\boxed {\boxed {\sf molarity \approx 3 \ M \ KCl}}

Explanation:

Molarity is a measure of concentration in moles per liter. The formula is:

molarity= \frac{moles \ of \ solute}{liters \ of \ solution}

We are given grams of solute and liters of solution, so we must convert both before calculating molarity.

<h3>1. Convert Grams to Moles</h3>

We convert grams to moles using the molar mass. This value is found on the Periodic Table. It is the same as the atomic mass, but the units are grams per mole (g/mol) instead of atomic mass units (amu).

We have the compound KCl, so we look up the molar masses of the individual elements.

  • Potassium (K): 39.098 g/mol
  • Chlorine (Cl): 35.45 g/mol

The compound does not contain subscripts, so we can add the molar masses together to find the molar mass of the compound.

  • Potassium chloride (KCl): 39.098+ 35.45= 74.548 g/mol

Use the molar mass as a ratio.

\frac {74.548 \ g\ KCl}{1 \ mol \ KCl}

Multiply by 140 grams of KCl.

140 \ g\ KCl*\frac {74.548 \ g\ KCl}{1 \ mol \ KCl}

Flip the ratio so the units of grams of KCl cancel.

140 \ g\ KCl*\frac{1 \ mol \ KCl} {74.548 \ g\ KCl}

140 *\frac{1 \ mol \ KCl} {74.548 }

1.877984654 \ mol \ KCl

<h3>2. Convert Milliliters to Liters</h3>

1 liter contains 1000 milliliters. Create another ratio.

\frac{ 1 \ L}{1000 \ mL}

Multiply by 600 milliliters (the value we are converting).

600 \ mL *\frac{ 1 \ L}{1000 \ mL}

The units of milliliters cancel.

600 \ *\frac{ 1 \ L}{1000 }

0.6 \ L

<h3>3. Calculate Molarity</h3>

Now we know the moles of solute and the liters of solution.

  • 1.877984654  mol  KCl and 0.6 L

Substitute the values into the molarity formula.

molarity= \frac {1.877984654 \ mol \ KCl}{0.6 \ L}

molarity= 3.129974424 \ mol \ KCl/L

The original measurements of grams and milliliters have 2 and 1 significant figures. We must round our answer to the least number of sig figs: 1.

For the number we found, that is the ones place. The 1 in the tenths place tells us to leave the 3 in the ones place.

molarity \approx 3 \ mol \ KCl/L

1 mole per liter is equal to 1 molar or M. Convert the units.

molarity \approx 3 \ M \ KCl

The molarity is approximately <u>3 M KCl.</u>

You might be interested in
What is the guiding formula for combustion reactions​
IgorLugansk [536]

Answer:

Explanation: so a combustion occurs when we react a substance with oxygen .you commonly call this "burning'' .therefore combustion will always include oxygen in the equation and the product will include carbon dioxide and give off water vapours

Therefore the general equation for a complete combustion reaction would be

Fuel + O2 ------ CO2 + H2O

8 0
3 years ago
Write an informal definition of half-life.
Pavel [41]

the time required for the activity of a substance taken into the body to lose one half its initial effectiveness. Informal. a brief period during which something flourishes before dying out.

hope this helps ^^

6 0
2 years ago
List all orbitals from 1s through 5s according to increasing energy for multielectron atoms. rank orbitals from smallest to larg
GaryK [48]

Answer:

1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s

Explanation:

You can predict the order of orbital energies by constructing a diagram as shown below.

Follow the arrows to get the orbitals in order of increasing energy.

The order is

1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s

3 0
3 years ago
What is standard pressure in atmospheres?<br><br> a.10<br> b.1<br> c.5<br> d.2
lesya [120]
The answer is d. 2 hope this helps
6 0
3 years ago
Please help meeeee!!!!!!!
irina [24]

Answer: Non-renewable energy comes from sources that will run out or will not be replenished in our lifetimes—or even in many, many lifetimes.

Most non-renewable energy sources are fossil fuels: coal, petroleum, and natural gas. Carbon is the main element in fossil fuels. For this reason, the time period that fossil fuels formed (about 360-300 million years ago) is called the Carboniferous Period.

All fossil fuels formed in a similar way. Hundreds of millions of years ago, even before the dinosaurs, Earth had a different landscape. It was covered with wide, shallow seas and swampy forests.

Plants, algae, and plankton grew in these ancient wetlands. They absorbed sunlight and created energy through photosynthesis. When they died, the organisms drifted to the bottom of the sea or lake. There was energy stored in the plants and animals when they died.

Over time, the dead plants were crushed under the seabed. Rocks and other sediment piled on top of them, creating high heat and pressure underground. In this environment, the plant and animal remains eventually turned into fossil fuels (coal, natural gas, and petroleum). Today, there are huge underground pockets (called reservoirs) of these non-renewable sources of energy all over the world.

Advantages and Disadvantages

Fossil fuels are a valuable source of energy. They are relatively inexpensive to extract. They can also be stored, piped, or shipped anywhere in the world.

However, burning fossil fuels is harmful for the environment. When coal and oil are burned, they release particles that can pollute the air, water, and land. Some of these particles are caught and set aside, but many of them are released into the air.

Burning fossil fuels also upsets Earth’s “carbon budget,” which balances the carbon in the ocean, earth, and air. When fossil fuels are combusted (heated), they release carbon dioxide into the atmosphere. Carbon dioxide is a gas that keeps heat in Earth’s atmosphere, a process called the “greenhouse effect.” The greenhouse effect is necessary to life on Earth, but relies on a balanced carbon budget.

The carbon in fossil fuels has been sequestered, or stored, underground for millions of years. By removing this sequestered carbon from the earth and releasing it into the atmosphere, Earth’s carbon budget is out of balance. This contributes to temperatures rising faster than organisms can adapt.

6 0
2 years ago
Other questions:
  • What is the mass of 1.0 x 10-3 mole of Zn? 3.9 x 1022 0.065 0.000015
    14·2 answers
  • What is the name of the compound PbS2 • 4H2O?
    14·1 answer
  • Could a 3 ion of aluminum be made by adding three protons to an aluminum atom
    10·1 answer
  • What is the thin structure that surrounds a cell?​
    13·1 answer
  • What is the mass, in g, of 27.2 mol of N? Be sure to answer all parts. Enter your answer in scientific notation. x 10 (select) A
    7·1 answer
  • What is the current produced when a 12-Volt battery encounters a resistance of 20 Ohms?
    10·1 answer
  • Ra/te me from 0 - 10<br> Im bored girls and guys<br> (i dont judge) :)
    14·1 answer
  • You start with an equimolar mixture of the gases SO₂ and O₂ in a container. The SO₂ and O₂ react to completion to form SO₃. If t
    11·1 answer
  • How do sound waves travel? PLEASE HELP IF YOU WANT BRAINLEIST AND ME TO LIKE URE COMMENT!!
    14·1 answer
  • In what ways can geographic position be considered a temperature control?
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!