IGCSE Double C10 Quiz

What two compounds test for water?

• "Anhydrous cobalt(II) chloride and anhydrous copper(II) sulfate"
• "Sugar and salt"
• "Iron filings and sand"
• "Vinegar and baking soda"

What is the color change of anhydrous copper(II) sulfate in water?

• "White to blue"
• "Blue to white"
• "Red to green"
• "No change"

What is the color change of anhydrous cobalt(II) chloride in water?

• "Blue to pink"
• "Pink to blue"
• "Yellow to purple"
• "No change"

What is the melting point of pure water?

• "0'C"
• "100'C"
• "-10'C"
• "25'C"

What happens to the melting point of water when you add impurities?

• "The melting point decreases and broadens
• "The melting point increases"
• "The melting point remains the same"
• "The melting point becomes sharper"

What is the boiling point of pure water?

• "100'C"
• "0'C"
• "50'C"
• "212 K"

What happens to the boiling point of water when you add impurities?

• "The boiling point increases and broadens
• "The boiling point decreases"
• "The boiling point remains the same"
• "The boiling point becomes sharper"

Why do we use distilled water for practicals and not tap water?

• "Tap water has more ions that can interfere with reactions
• "Distilled water is cheaper"
• "Tap water is more pure"
• "Tap water has no minerals"

What does domestic water supply mean?

• "Clean water used at home
• "Water from rivers and lakes"
• "Water used in factories"
• "Water that is dirty and unusable"

How are solids removed when making domestic water supply?

• "Sedimentation and filtration
• "Boiling"
• "Adding sugar"
• "Freezing"