Everyday Chemistry Applications

Why does ice float in water?

• Heavier than water
• Air inside ice
• Ice is less dense
• Water is compressed

Answer explanation

Ice forms a spacious structure due to hydrogen bonds.

What causes water to expand when it freezes?

• Air pressure
• Hydrogen bonding
• Salt content
• Low temperature

Answer explanation

Hydrogen bonds create a loose structure in ice.

Why does salt help in melting ice below 0°C?

• Absorbs sunlight
• Reacts with air
• Lowers freezing point
• Adds heat

Answer explanation

It breaks water bonds, allowing melting at lower temps.

What gas is formed when baking soda reacts with acid?

• Oxygen
• Carbon dioxide
• Hydrogen
• Nitrogen

Answer explanation

CO₂ gas makes cakes and breads rise.

Why does baking powder work without extra acid?

• Has water
• Has base only
• Has both acid and base
• Reacts with sugar

Answer explanation

It contains both ingredients needed to produce CO₂.

How does soap clean oily stains?

• Makes water hot
• Melts oil
• Forms micelles
• Changes oil color

Answer explanation

Soap forms micelles that trap oil and wash it away.

What part of soap molecule sticks to grease?

• Acid end
• Water end
• Oil-loving tail
• None

Answer explanation

The tail part sticks to grease and removes it.

Why does vinegar + baking soda bubble?

• Heat forms
• Light forms
• CO₂ gas forms
• Liquid forms

Answer explanation

The fizzing is from CO₂ released in the reaction.

What type of reaction is vinegar and baking soda?

• Physical change
• Acid–base reaction
• Dissolving
• Freezing

Answer explanation

It's a chemical reaction that produces gas.