Questions
When a burning ribbon of a metal was taken in a jar containing gas, it formed white and black powder. The white powder can be used as medicine to cure hyperacidity.
- What happens when the white substance is dissolved in water? Write only balanced chemical equation.
- How does the solution help to reduce the hyperacidity of stomach?
In the given graph, some substances and their specific heat capacities are shown in J/kg$\rm ^{\circ}$C. Calculate the change in temperature of 1kg mass of substance C when heated by equal amount of heat required to raise the temperature of 1kg mass of substance B from 10 °C to 50 °C.
Amphioxus is an animal of sub-phylum cephalochordata. How does it link with vertebrates and evolution? Write one point for each.
Two persons use the same tap water to wash the clothes. Person A used soap and hot (boiled) water while person B used cold water and detergent. Give any one reason for using hot water by person 'A' and using detergent by persons 'B'.
If we have to do the following task during extraction of metal from its ore, which procedure can be used?
- To change the ore into metallic oxide.
- To separate hydrophilic and hydrofobic substances from the ore.
Write the balanced chemical equation for the reaction between aluminium and dilute hydrochloric acid.
'Birth and death of stars was not possible in the absence of gravitational force', justify the statement in two points.
The weight of displaced water is equal to the weight of the floating body on the water. Justify it with diagram.
Write any two differences between autosome and sex chromosome.
Write any two differences between amphibian and reptiles.