7. A dilute solution of which acid is most likely to produce a reduction product other than H2 when it reacts with a metal? (A) HF (B) HCI HNO3 (D) H2SO4 Solution Dilute nitric acid reacts with metals to produce hydrogen gas, but not all metals. Magnesium, manganese and zinc react to give hydrogen gas and the corresponding nitrate. But copper reacts with dilute nitric acid to give nitric oxide which subsequently reacts with atmospheric oxygen to give nitrogen dioxide. Concentrated nitric acid reacts with copper giving nitrogen dioxide directly as product. When attempting to react nitric acid with less electropositive metals, products obtained can depend on reaction temperature as well as the metal involved. Some metals and metalloids react with nitric acid to give the oxides eg. Sn & Tl. Precious metals such as gold and other platinum group metals do not react with nitric acid. Chromium, iron and aluminium readily dissolves in dilute nitric acid, but passivates in concentrated nitric acid. .

1. 7. A dilute solution of which acid is most likely to produce a reduction product other than H2
when it reacts with a metal? (A) HF (B) HCI HNO3 (D) H2SO4
Solution
Dilute nitric acid reacts with metals to produce hydrogen gas, but not all metals.
Magnesium, manganese and zinc react to give hydrogen gas and the corresponding nitrate.
But copper reacts with dilute nitric acid to give nitric oxide which subsequently reacts with
atmospheric oxygen to give nitrogen dioxide.
Concentrated nitric acid reacts with copper giving nitrogen dioxide directly as product.
When attempting to react nitric acid with less electropositive metals, products obtained can
depend on reaction temperature as well as the metal involved.
Some metals and metalloids react with nitric acid to give the oxides eg. Sn & Tl.
Precious metals such as gold and other platinum group metals do not react with nitric acid.
Chromium, iron and aluminium readily dissolves in dilute nitric acid, but passivates in
concentrated nitric acid.