27. what
happens when
magnesium
react with
hot water
28. what happens when metals react with
Acide
29. Hydragen
gen is not evalued when a metal
reacts with nitric acid why?
30. why the copper
did not react with dilute
HCL
31. what is Aqua regia?
Answers
Answer:
27).Magnesium reacts with hot water much faster to produce magnesium hydroxide and hydrogen gas.
28).When an acid reacts with metal, a salt and hydrogen are produced: acid + metal → salt + hydrogen
29).Hydrogen gas is not evolved when a metal reacts with nitric acid. It is because HNO3 is a strong oxidising agent.
30).As copper is less reactive than hydrogen, therefore it will not liberate hydrogen gas from the acids like HCl, HNO. But sulphuric acid is a strong oxidising agent, therefore it will oxidise copper metal to Cu2+ ion
31). A mixture of concentrated nitric and hydrochloric acids. It is a highly corrosive liquid able to attack gold and other resistant substances.
Hope it helps you,
27.Increasing temperature increases the rate of reaction. The reaction between magnesium and cold water is very slow. Magnesium reacts with hot water much faster to produce magnesium hydroxide and hydrogen gas.
28.When an acid reacts with metal, a salt and hydrogen are produced: acid + metal → salt + hydrogen An example: nitric acid + calcium → calcium nitrate + hydrogen The salt that is produced depends upon which acid and which metal react.
29.Hydrogen gas is not evolved when a metal reacts with nitric acid. It is because HNO3 is a strong oxidising agent. It oxidises the H2 produced to water and itself gets reduced to any of the nitrogen oxides (N2O, NO, NO2).
30.As copper is less reactive than hydrogen, therefore it will not liberate hydrogen gas from the acids like HCl, HNO. But sulphuric acid is a strong oxidising agent, therefore it will oxidise copper metal to Cu2+ ion. ... Hence it does not react with copper metal at all.
31.a mixture of concentrated nitric and hydrochloric acids. It is a highly corrosive liquid able to attack gold and other resistant substances.