Explanation

Graham's Law of Diffusion states that the rate of diffusion of a gas is inversely proportional to the square root of its molar mass.

$$\text{<font color="\#0000ff"><b>Rate</b></font>}<font\; color="\#0000ff"><b>\propto </b></font>\frac{\mathrm{<font\; color="\#0000ff"><b>1</b></font>}}{\sqrt{\mathrm{<font\; color="\#0000ff"><b>M</b></font>}}}$$

Compare molar masses:

CH₄ (Methane): 16 g/mol

N₂ (Nitrogen): 28 g/mol

O₂ (Oxygen): 32 g/mol

H₂ (Hydrogen): 2 g/mol (lightest)

Since H₂ has the smallest molar mass, it diffuses the most rapidly.

Explanation

Hydrochloric acid (HCl) is a strong acid that completely dissociates in water, releasing H⁺ ions.

The pH scale ranges from 0 to 14, where pH < 7 indicates acidity.

Since HCl increases H⁺ concentration, its pH is always less than 7.

Explanation

Systematic errors are caused by faulty or improper functioning of instruments, or by a flaw in the experimental design.

These errors are consistent and repeatable, and can be identified and corrected.

Explanation

• Au comes from the Latin word aurum, meaning "gold" (from "glowing dawn")
• Atomic number: 79
• Belongs to group 11 
• Category: transition metal

Additional information:

• Atomic mass: 196.97 u
• Melting point: 1,064°C
• Boiling point: 2,856°C
• Density: 19.3 g/cm³ (very heavy)

Explanation

Evaporation is the process where liquid water turns into water vapour due to heat.

It is a key part of the water cycle, occurring from surfaces like oceans, lakes, and soil.

Explanation

Iron is the most used metal in construction, machinery, and tools.

Its alloy, steel, is the backbone of modern industry.

Explanation

Oxygen is not an element in the 3rd period of the periodic table. 

Oxygen is in the second period. 

The elements in the 3rd period are:

• Sodium (Na),
• Magnesium (Mg),
• Aluminum (Al),
• Silicon (Si),
• Phosphorus (P),
• Sulfur (S),
• Chlorine (Cl),
• Argon (Ar). 

Explanation

When an aldehyde is oxidized, it typically converts to a carboxylic acid.

This reaction involves the addition of an oxygen atom to the aldehyde, changing the carbonyl group (C=O) at the end of the carbon chain into a carboxyl group (–COOH).

Explanation

The compound called ethyl ethanoate is the chemical known as ethyl acetate.

Chemical Formula: CH₃COOCH₂CH₃ or C₄H₈O₂ 

Appearance: A clear, colorless, volatile, and flammable liquid. 

Odor: It has a characteristic sweet, fruity smell, often described as similar to pear drops. 

Origin: It is the ester formed from the reaction of ethanol (ethyl alcohol) and acetic acid (ethanoic acid). 

Uses:

Solvent: Ethyl acetate is a common solvent in various applications, including paints, coatings, and adhesives. 

Explanation

The first member of the alkane series is methane (CH₄).

Alkanes are saturated hydrocarbons characterized by single bonds between carbon atoms, with methane being the simplest example in this homologous series.