The color of an aqueous solution of zinc sulphate as observed in the laboratory is:

• Green 

• Yellow 

• Blue

• Blue

What are the various steps in a food chain called?

Acetic acid solution turns: 

• blue litmus red 

• red litmus blue 

• blue litmus colourless 

• blue litmus colourless 

What makes the earth’s atmosphere a heterogeneous mixture?

A yeast cell in which budding occurs was seen to have: 

• one bud cell 

• two bud cell 

• three bud cell 

• three bud cell 

On adding NaHCO₃ to acetic acid, a gas is evolved which turns lime water milky due to the formation of:

• Calcium bicarbonate 

• Calcium hydroxide

• Calcium carbonate 

• Calcium carbonate 

Acetic acid smells like: 

• a banana 

• Vinegar

• an orange

• an orange

Write the electron dot structure of ethane molecule, C₂H₆.

What is the important function of the presence of ozone in earth’s atmosphere?

To show that zinc is a more active metal than copper, the correct procedure is to: 

• Add dilute nitric acid on strips of both the metals. 

• Observe transmission of heat through strips of zinc and copper. 

• Prepare a solution of zinc sulphate and hang a strip of copper into it. 

• Prepare a solution of zinc sulphate and hang a strip of copper into it.