MEDIUM
8th West Bengal Board
IMPORTANT
Earn 100

No reaction occurs when dry baking soda and powdered oxalic acid are mixed together; but when water is added to this mixture reaction occurs rapidly with effervescence of carbon dioxide. What may be the reason for it?

Important Questions on Sample Questions

MEDIUM
8th West Bengal Board
IMPORTANT
Environment and Science Class 8>Chapter 12 - Sample Questions>Sample Questions>Q 6
Write down the equation for chemical reaction when hydrogen gas is passed over hot cupric oxide.
MEDIUM
8th West Bengal Board
IMPORTANT
Environment and Science Class 8>Chapter 12 - Sample Questions>Sample Questions>Q 6
Write down the names of two food items where ginger, garlic and onion are used while cooking?
MEDIUM
8th West Bengal Board
IMPORTANT
Environment and Science Class 8>Chapter 12 - Sample Questions>Sample Questions>Q 6
Write down two differences between major and minor carp.
MEDIUM
8th West Bengal Board
IMPORTANT
Environment and Science Class 8>Chapter 12 - Sample Questions>Sample Questions>Q 6
What are the natural processes by which the nutrients lost from the soil can be replenished?
MEDIUM
8th West Bengal Board
IMPORTANT
Environment and Science Class 8>Chapter 12 - Sample Questions>Sample Questions>Q 6
How do bacteria help in waste treatment?
MEDIUM
8th West Bengal Board
IMPORTANT
Environment and Science Class 8>Chapter 12 - Sample Questions>Sample Questions>Q 6
What is the reason behind RBC being rounded and flattened on both sides?
EASY
8th West Bengal Board
IMPORTANT
Environment and Science Class 8>Chapter 12 - Sample Questions>Sample Questions>Q 7
Why air bubbles look shiny in water?
MEDIUM
8th West Bengal Board
IMPORTANT
Environment and Science Class 8>Chapter 12 - Sample Questions>Sample Questions>Q 7
You have no means (pot) with you to keep your food hot for a long time. But you need to do it. What measures will you take to do it? Why do you undertake the measures?