Brass is an alloy of zinc and copper. Copper does not react with dilute sulfuric acid, while zinc can.
When the content of zinc is less than 35%, zinc can be dissolved in copper to form single-phase A, which is called single-phase brass. Good plasticity, suitable for cold and hot pressing.
When the content of zinc is 36%~46%, there are single-phase and β solid solutions mainly composed of copper and zinc, which are called biphase brass. β phase reduces the plasticity of brass and improves the tensile strength, so it is only suitable for hot pressing.
In iron brass, iron precipitates in the form of iron-rich particles, which are used as crystal nuclei to refine grains and prevent recrystallization grains from growing, thus improving the mechanical properties and technological properties of the alloy. The iron content in iron brass is usually below 1.5%, and its structure is (α+β), which has high strength and toughness, good plasticity at high temperature and cold deformation. The commonly used brand number is Hfe59- 1- 1.
Extended data:
Dilute sulfuric acid makes purple litmus turn red, because dilute sulfuric acid is acidic, and acid can make litmus change color, and colorless phenolphthalein remains unchanged.
Because of its corrosiveness, it can also be used for rust removal. (Fe？ o？ +3H？ So what? =Fe？ (So? )? +3H？ o)
Dilute sulfuric acid can react with active metals to generate hydrogen;
Fe+ H？ So what? = FeSO？ + H？ ↑ (Note: concentrated sulfuric acid will passivate iron, so it cannot react)
Zn+ H？ So what? = ZnSO？ + H？ ↑
Mg+ H？ So what? = MgSO？ +H？ ↑
2Al + 3H？ So what? = Al？ (So? )? + 3H？ ↑
Can be reduced to hydrogen sulfide in some cases:
4Mn+5H？ So what? =4MnSO？ +H？ O+H？ S↑
Interaction with basic oxides:
Dilute sulfuric acid can react with alkaline oxides to form salt and water.
MgO + H？ So what? = MgSO？ + H？ O
CuO+ H？ So what? = CuSO？ + H？ O
Reaction with alkali:
h？ So what? + 2NaOH = Na？ So what? + 2H？ O
h？ So what? + 2KOH =K？ So what? + 2H？ O
h？ So what? +Ca (oh)? =CaSO？ +2H？ O (calcium sulfate is slightly soluble in water)
Baidu encyclopedia-dilute sulfuric acid
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