In general what two classes of materials dissolve in water

Which of the following is a chemical change?

FromTheMoon [43]

<u>Answer:</u>

<em>Silver tarnishing as the silver metal reacts with sulphur is a chemical change.</em>

<u>Explanation:</u>

Tarnishing is the process of chemical change occurring on the surface of objects leading to corrosion or other defects on the surface. The remaining options like dilution, eroding is a physical change where the concentration of salt and rock particles will be decreased, respectively.

Similarly for soil drying also the concentration of water will be decreased leading to a physical change from wetty or dry soil.

But the last option which indicates tarnishing of silver metal on reaction with sulphur is a chemical process as the surface of silver metal will be reacting to sulphur and leads to lose of electrons which leads to corrosion of the surface or tarnishing of silver.

4 0

3 years ago

Read 2 more answers

Why is coke sprinkled on the top of electrolyte in the bayer's process?

Vesnalui [34]

Powdered coke prevent the heat loss. As a result, it prevents burning of carbon electrodes.

4 0

1 year ago

This is very urgent please hurry!!?!!??!

yawa3891 [41]

Answer:

The greatest acceleration when the unbalanced force is applied will be experienced in :

A) The box with a mass of 2 kg

Explanation:

According to second law of motion the external unbalanced force is directly proportional to rate of change of momentum.

F = (Final momentum - initial momentum)/time

or

Force is equal to the product of mass and acceleration

F = m x a

Here a= acceleration

m = mass of the object

If Force is constant then acceleration is inversely proportional to mass

$a =\frac{F}{m}$

A) The box with a mass of 2kg

F = 8 N

$a =\frac{8}{2}$

a = 4 m/s2

B) The box with the mass of 4kg

$a =\frac{8}{4}$

a = 2 m/s2

C) The box with a mass of 6kg

$a =\frac{8}{6}$

a = 1.33 m/s2

D) The box with a mass of 8kg

$a =\frac{8}{8}$

a = 1 m/s2

3 0

3 years ago

Liquid octane CH3CH26CH3 will react with gaseous oxygen O2 to produce gaseous carbon dioxide CO2 and gaseous water H2O . Suppose

Slav-nsk [51]

Answer:

The minimum mass of octane that could be left over is 43.0 grams

Explanation:

Step 1: Data given

Mass of octane = 73.0 grams

Mass of oxygen = 105.0 grams

Molar mass octane = 114.23 g/mol

Molar mass oxygen = 32.0 g/mol

Step 2: The balanced equation

2C8H18 + 25O2 → 16CO2 + 18H2O

Step 3: Calculate the number of moles

Moles = mass / molar mass

Moles octane = 73.0 grams / 114.23 g/mol

Moles octane = 0.639 moles

Moles O2 = 105.0 grams / 32.0 g/mol

Moles O2 = 3.28 moles

Step 4: Calculate the limiting reactant

For 2 moles octane we need 25 moles O2 to produce 16 moles CO2 and 18 moles H2O

O2 is the limiting reactant. It will completely be consumed. (3.28 moles). There will react 3.28 / 12.5 = 0.2624 moles. There will remain 0.639 - 0.2624 = 0.3766 moles octane

Step 5: Calculate mass octane remaining

Mass octane = moles * molar mass

Mass octane = 0.3766 moles * 114.23 g/mol

Mass octane = 43.0 grams

The minimum mass of octane that could be left over is 43.0 grams

3 0

2 years ago

The jet stream is one of the key winds that moves air masses. in which direction does the jet stream in the united state general

OleMash [197]

The jet stream is one of the key winds that moves air masses at the direction from west to east it moves.

<h3>What are jet streams?</h3>

Jet streams are strong winds which are flow in the form of narrow bands in the upper part of the atmosphere. On the earth these winds are flows near the altitude of the tropopause. These winds carries weather systems and blows toward the colder northern air and due to the rotation of earth, its direction is from west to east.

Hence jet streams move winds from west to east direction.

To know more about jet streams, visit the below link:
brainly.com/question/791542

7 0

1 year ago