If the solvent front is 68 mm and the ring front of an unknown is 48mm from the original spot, what is the rf value?

Answer:

D. Force

Explanation:

Applied force can cause change in direction

A force applied at an angle to the direction of motion of an object can cause it to change direction. It is possible that the object keeps going at the same speed, if the force is applied perpendicular to the direction of motion. But the velocity of the the object changes.

Answer:

10.7 g of KOH

Explanation:

First of all, we determine the reaction:

2K (s) + 2H₂O(l) → H₂(g) + 2KOH(aq)

We convert the mass of K, to moles → 7.5 g . mol/39.1 g = 0.192 moles

Ratio is 2:2, so the moles I have of K must produce the same moles of KOH. In this case, the produces moles of KOH are 0.192 moles.

We convert the moles to mass, to finish the answer:

0.192 mol . 56.1g /1mol = 10.7 g of KOH

is the correct statement that describes the particles of an ideal gas on the basis of kinetic molecular theory.

Further Explanation:

Kinetic theory of gases

It defines gas to be considered as a large number of particles. These particles move randomly in all directions. It explains the macroscopic properties of gases by considering their molecular composition and motion.

Postulates:

(a) The gas molecules are very small and are located far apart from each other. Most of the volume occupied by the gas is an empty space.

(b). The molecules of the gas are in rapid random motion. These can move in all directions.

(c). The gas molecules undergo collisions with each other and with the walls of the container. The collisions between molecules and container walls are responsible for the pressure of the gas.

(d). There is no loss of kinetic energy when gas molecules collide so their collisions are known as perfectly elastic.

(e). No interaction occurs between different gas particles during collisions.

(1) The gas particles are relatively far apart and have negligible volume.

The size of gas particles is very small and therefore these have negligible volume. Moreover, these molecules are far away from each other.

(2) The gas particles are in constant, nonlinear motion.

The motion of the gas particles occurs randomly in all directions so they can not be in constant, nonlinear motion.

(3) The gas particles have attractive forces between them.

The particles of gas have no interaction with each other. So no attractive forces are present between them.

(4) The gas particles have collisions without transferring energy.

The collisions of gas molecules are considered to be perfectly elastic. So the total energy of the system remains constant. It neither increases nor decreases.

Therefore the correct statement is (1).

Learn more:

1. Which will have the greatest average speed at 355 K?: brainly.com/question/1852048
2. Which statement is true for Boyle’s law: brainly.com/question/1158880

Answer details:

Grade: High School

Subject: Chemistry

Chapter: Ideal gas equation

Keywords: kinetic theory of gases, collisions, energy, constant, attractive forces, particles, molecules, volume, random motion, perfectly elastic, negligible.

Answer:

(1) The gas particles are relatively far apart and have negligible volume

Explanation:

The Kinetic Molecular Theory was formulated to explain the behaviour of ideal gases. The main postulates of the theory are:

-The volume occupied by the gases is negligible when compared to the distance between them

- They do not experience any intermolecular forces of attraction or repulsion

-The collision between gas particles is completely elastic

-The gas particles are in constant random motion

Therefore the first statement which suggests that the gas particles are relatively far apart and have negligible volume is in accordance with the theory

a) Degree of unsaturation: 5.

C8H8 corresponds to the saturated alkane C8H18, octane, which has eight hydrogen atoms per molecule. Theoretically, it will take five hydrogen molecules H2 to convert C8H8 to C8H18. C8H8 therefore has and DoU of 5.

b) Number of triple bonds: 2.

Only triple bonds are hydrogenated over a Lindlar catalyst. A triple bond can be converted only to a double bond, but not a single bond, under such settings. Each triple bond would absorb only one molecule of hydrogen.

Two hydrogen molecules are absorbed for each C8H8 molecule. Each molecule therefore contains two triple bonds.

c) Number of double bonds: 1.

Palladium catalysts convert both triple and double bonds to single bonds while preserving any rings. Each triple bond would consume two hydrogen molecules, whereas each double bond would consume one.

The two triple bonds as determined in b) account for the consumption of four out the five hydrogen molecules. One double bond shall be responsible for the other.

d) There is no ring in C8H18.

The molecular formula of C8H18 indicates an DoU of five. Each double bond contributes to the DoU by one, each triple bond by two. The double bond and the two triple bonds would have accounted for all five degrees of unsaturation. There are thus no spare DoU available for the presence of rings.

Final answer:

The described hydrocarbon with formula C8H8 has 4 degrees of unsaturation initially, indicating the presence of 2 triple bonds converted by Lindlar catalyst. The remaining 2 degrees of unsaturation are attributed to a ring structure.

Explanation:

The concept being evaluated here is degrees of unsaturation (also known as the index of hydrogen deficiency) in organic molecules and how they refer to the number of double bonds, triple bonds, or rings that a molecule contains.

At first, we can calculate the Index of Hydrogen Deficiency (IHD) which is calculated using the formula (2C+2+X-N)/2, where C is the number of Carbon atoms, X is the halogens and N is the nitrogens. For a molecule with formula C8H8, this equates to (2×8+2-8)/2 = 4. Therefore, your hydrocarbon has 4 degrees of unsaturation.

Now, considering the information that under Lindlar catalyst, the compound absorbed 2 equivalents of H2, which suggests the presence of 2 triple bonds converted to 2 double bonds. This leaves us with 2 degrees of unsaturation which must be in the form of a ring. However, on hydrogenation over a palladium catalyst, 5 equivalents of H2 indicate that these 2 double bonds from the Lindlar reaction and the ring can convert completely to single bonds. So, In summary: a) Degrees of unsaturation: 4 b) Triple bonds: 2 c) Double bonds: 0 (after Lindlar hydrogenation) d) Number of Rings: 1

Learn more about Degrees of Unsaturation here:

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