🌡️Chemistry Challenge”🧫

Pressure

100

What is the SI unit of pressure?

Pascal

200

Which instrument is used to measure air pressure?

Barometer

300

A force of 120 newtons (N) is exerted uniformly on an area of 0.6 square meters (m²).
What is the pressure of the air acting on the surface in pascals (Pa)?

200 Pa

400

Why does pressure increase when the area decreases?

Because the same force acts on a smaller area.

500

A diver’s air bubble is 3.0 L at 1 atm. What is its volume at 3 atm? (Use P₁V₁=P₂V₂)

1.0 L

Gas Laws

100

This law says that the volume of a gas is directly proportional to its absolute temperature at constant pressure.

Charles’s Law

200

True/False

According to kinetic theory, pressure results from this action of gas molecules on container walls. 

True

Pressure in gases, according to KMT, comes from the continuous and elastic collisions of moving gas particles with the container walls.

300

In PV = nRT, this letter stands for the gas constant, typically 0.082057 L·atm·mol⁻¹·K⁻¹.

It is the R or the ideal gas constant.

400

A 1.00 L flask of gas at 2.00 atm is heated from 300 K to 450 K at constant volume. What is the final pressure

P₂ = P₁ × T₂/T₁ 

    = 2.00 × 450/300 = 3.00 atm

500

A 5.00 L cylinder contains nitrogen at 2.00 atm and 273 K. How many moles are present?

n = PV/RT 

   = (2.00)(5.00)/(0.08206×273) ≈ 0.446 mol

Quantum Numbers

100

What is the maximum number of electrons that occupy f sublevel?

7 orbital * 2 electrons=14

200

Two electrons occupy the same 4p orbital. Using quantum numbers, explain how their spins differ.

Their ms values must be opposite, one + 1/2and one −1/2, according to the Pauli Exclusion Principle.

300

An electron has n=4, l=1, ml=0, ms= +1/2. Predict how many other electrons can share the same n and l but differ in ml and ms.

There are 5 other electrons:

l=1 (p-orbital) has 3 possible ml values (-1, 0, +1). Each ml can hold 2 electrons with opposite ms.

400

If an electron has (n=5, l=2, mₗ=0, mₛ=+½), what orbital is it in?

5d orbital

500

Given an electron in a 3d orbital, justify why it cannot have l=3.

For a given n, ℓ must satisfy 0 ≤ ℓ ≤ n−1. For n=3, ℓ can only be 0, 1, or 2; ℓ =3.

Lewis Structure

100

What type of bond is formed when atoms share electrons?

Covalent bond

200

Draw the Lewis structure of the chloride ion (Cl⁻) and explain why it carries a negative charge.

300

Draw the Lewis structure of CO₂. How many double bonds are in the molecule?

2 double bonds

400

Which atom is usually placed at the center of a Lewis structure?

The least electronegative atom.

500

When an atom cannot achieve an octet of electrons, it does not become stable. What usually happens to it?

It becomes reactive.

Structural Isomerism

100

What are isomers?

Compounds with the same formula but different structures.

200

Classify the type of isomerism (if any) shown by the compounds below.

Not an isomer.

300

What is positional isomerism?

Isomers differ in the position of a functional group or double bond or substituent.

400

Classify the type of isomerism (if any) shown by the compounds below.

Positional Isomerism

500

Are the compounds shown below isomers?

Yes