What are amphoteric oxides? Choose the amphoteric oxides amongst the following:
Na2O, ZnO, Al2O3, CO2, H2O
Important Questions on Sample Paper-1
The elements Li, Na, and K having one valence electron are in period 2,3 and 4 respectively of modern periodic table.
In which group of the periodic table they should be?
The elements Li, Na, and K having one valence electron are in period 2,3 and 4 respectively of modern periodic table.
Which one of them is least reactive?
The elements Li, Na, and K having one valence electron are in period 2, 3 and 4 respectively of modern periodic table.
Which one of them has largest atomic radius? Give reason to justify your answer.
A carboxylic acid C2H4O2 reacts with an alcohol in the presence of H2SO4 to form a compound X. The alcohol on oxidation with alkaline KMnO4 followed by acidification gives the same carboxylic acid C2H4O2. Write the name and structure of-
i) Carboxylic acid
ii) Alcohol
iii) Compound X
Five solutions A, B, C, D and E when tested with universal indicator showed pH as 4, 1, 11, 7 and 9 respectively. Which solution is
a) neutral
b) strongly alkaline
c) strongly acidic
d) weakly acidic
e) weakly alkaline
State the reason why
Carbon is not used to reduce the oxides of sodium and aluminium?
State the reason why-
An iron strip dipped in a blue copper sulphate solution turns the blue solution to pale green.
State the reason why-
Metals replace hydrogen from acids whereas non-metals do not.
