Zn(s)+Cu^2+(aq)—->Zn^2+(aq)

If a sample of sodium chloride with a mass of

alex41 [277]

Original molarity was 1.7 moles of NaCl

Final molarity was 0.36 moles of NaCl

Given Information:

Original (concentrated) solution: 25 g NaCl in a 250 mL solution, solve for molarity

Final (diluted) solution: More water is added to make the new total volume 1.2 liters, solve for the new molarity

1. Solve for the molarity of the original (concentrated) solution.

Molarity (M) = moles of solute (mol) / liters of solution (L)

Convert the given information to the appropriate units before plugging in and solving for molarity.

Molarity (M) = 0.43 mol NaCl solute / 0.250 L solution = 1.7 M NaCl (original solution)

2. Solve for the molarity of the final (diluted) solution.

Remember that the amount of solute remains constant in a dilution problem; it is just the total volume of the solution that changes due to the addition of solvent.

Molarity (M) = 0.43 mol NaCl solute / 1.2 L solution

Molarity (M) of the final solution = 0.36 M NaCl

I hope this helped:))

6 0

2 years ago

What is the kinetic energy of a 5 kg object moving at 7 m/s?

valina [46]

Answer:

122.5 Joule, or 122.5 j

Explanation:

Given,

mass of the object (m) = 5 kg

velocity of the object (v) = 7 m/s

Kinetic energy = $\frac{1}{2}$ × m × v²

Applying the formula:

Kinetic energy = $\frac{1}{2}$ × 5 × 7²

⇒ $\frac{1}{2}$ × 5 × 7 × 7

⇒ $\frac{245}{2}$

⇒ 122.5 Joule, or 122.5 j

Kinetic energy is the energy that an object gains as the result of the motion. It also depends on the mass of the object and force with which the motion is applied. In the given question, the mass of the object is 5 kg and the force of the velocity by which it is moving is 7 m/s.

3 0

3 years ago

Basically everything is in the picture, and i dont really understand please help.

zubka84 [21]

This is what I found

5 0

3 years ago

Gaseous ethane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 9.32 g of ethane is

Pie

Answer:

There will remain 8.06 grams of ethane

Explanation:

Step 1: Data given

Mass of ethane = 9.32 grams

Mass of oxygen = 12.0 grams

Molar mass ethane = 30.07 g/mol

Molar mass oxygen = 32.00 g/mol

Step 2: The balanced equation

2 C2H6 + 7 O2 → 4 CO2 + 6 H2O

Step 3: Calculate moles ethane

Moles ethane = mass ethane / molar mass ethane

Moles ethane = 9.32 grams / 30.07 g/mol

Moles ethane = 0.3099 moles

Step 4: Calculate moles oxygen

Moles oxygen = 12.0 grams / 32.0 g/mol

Moles oxygen = 0.375 moles

Step 5: Calculate the limiting reactant

For 2 moles ethane we need 7 moles O2 to produce 4 moles CO2 and 6 moles H2O

O2 is the limiting reactant. It will completely be consumed ( 0.375 moles)

Ethane is in excess. There will react 2/7 * 0.375 = 0.107 moles

There will remain 0.375 - 0.107 = 0.268 moles

Step 6: Calculate mass ethane

Mass ethane = moles ethane * molar mass ethane

Mass ethane = 0.268 moles * 30.07 g/mol

Mass ethane = 8.06 grams

There will remain 8.06 grams of ethane

7 0

3 years ago

Pls help ASAP........ A student was roasting marshmallows over a fire. The student

Phantasy [73]

Answer:

A chemical change

Explanation:

The marshmallow turning brown and bubbling implies that a chemical change has taken place.

For chemical changes to occur, we observe any of the following:

a new kind of matter is formed.
it is always accompanied by energy changes
the process is not easily reversible
it involves a change in mass
requires considerable amount of energy.

ii. Two signs that shows a chemical change has taken place is that:

bubbles are being formed as it is roasted and it implies that new substances have been formed.
also, significant amount of heat energy is supplied for the roasting.

5 0

2 years ago