The knowledge points of magnesium and aluminum in the first year of high school

1.Magnesium knowledge points.

1) Physical properties: magnesium, chemical symbol MG, relative atomic mass of 24, silvery-white metal; Melting point.

The boiling point is 1107 °C, and the density is gram cm

2) Chemical properties: can react with halogen elements, such as: Mg+Cl2 ---ignition) MgCl2

Can react with oxygen: mg+O2 - mgo

It can be reflected with dilute acid: H2SO4 + MG==MGSo4 + H2 (gas).

It can be reflected with boiling water: mg+2h2o==mg(oh)2+h2(gas).

Note: Magnesium is located in the second main group of the third period, so you can find elements adjacent to it, all of which are similar in structural properties.

2. Biological aspect: It is an essential element of biological life and cannot be missing. In plants, it exists in an ionic state. New leaves contain more magnesium than older leaves.

2.Knowledge points of aluminum.

Al(OH)3 is an amphoteric hydroxide, a ternary weak base. It can also be seen as halo2+h2o, so that it can also be seen as a weak acid of one element.

Al(OH)3 can only react with strong acids and bases, and does not react with weak acids and bases (such as CO2+H20).

The question about Al3+ and ALO2- is also relatively simple, just think of Al(OH)3 as the corresponding acid-base.

Some other knowledge is relatively simple, just look at the books and notes.

Aluminum is hermaphroditic. There is also acid making, and the knowledge of the crystal is almost understood, hehe.

One of the key points of chemistry review is to use the perspective of elements to learn and understand substances, and to master more chemistry knowledge in order to master chemistry well. The following is the knowledge points of high school chemical aluminum that I have compiled for you, I hope it will be helpful to you.

Knowledge points of high school chemistry aluminum (1) 1. Aluminum.

1) Physical properties: low density, low melting point, low hardness, silvery-white metal.

2) Chemical Properties:

Reaction with O2 and other non-metals: Aluminum and its compounds have anti-corrosion ability due to the formation of oxide film in the air at room temperature. 4al+3o22al2o3 2al+3sal2s3

2Fe+ALO (thermite reaction).

With certain oxides: 2Al+Fe2O323

Reaction with water: 2Al+6H2O 2Al(OH)3+3H2 (generally does not react, only the oxide film is destroyed after the reaction).

Reaction with acid: 2Al+6H+3Al3+ +3H2 (at room temperature, passivated in concentrated H2SO4, concentrated HNO3) Reaction with strong alkali solution: 2Al+2NaOH+2H2O 2Naalo2+3H2 2, Al2O3 (amphoteric oxide):

White solid with high melting point.

Knowledge points of high school chemistry aluminum (2) 1Aluminum foil burns violently in oxygen.

4al+3o22al2o3

2.The aluminum sheet reacts with dilute hydrochloric acid.

2al+6hcl=2alcl3+3h2↑

2al+6h+=2al3++3h2↑

3.Aluminum reacts with a sodium hydroxide solution.

2al+2naoh+2h2o=2naalo2+3h2↑

2al+2oh-+2h2o=2alo2-+3h2↑

4.Aluminum reacts with ferric oxide at high temperature (thermite reaction) of aluminum and its compounds 2Al+Fe2O32Fe+Al2O3

Knowledge points of high school chemistry aluminum (3) 1The aluminum beam of the oxygen section is dissolved in the sodium hydroxide solution.

With grandchildren al2o3+2naoh2naalo2+h2o

al2o3+2oh-==2alo2-+h2o

2.Excessive ammonia water is dropped in the aluminum sulfate solution.

al2(so4)3+6nh3·h2o=2al(oh)3↓+3(nh4)2so4

al3++3nh3·h2o=al(oh)3↓+3nh4+

3., aluminum hydroxide solution with hydrochloric acid.

al(oh)3+3hcl=alcl3+3h2o

al(oh)3+3h+=al3++3h2o

Al(OH)3 reacts with NaOH solution:

al(oh)3+naoh(6)naalo2+2h2oal(oh)3+oh-=alo2-+2h2o

mg+cl2===mgcl2

mg+br2===mgbr2

2mg+o2===2mgo

mg+s===mgs

mg+2h2o===mg（oh）2+h2

2mg+TIC4(melted)===Ti+2mgCl2mg+2RBCl===MgCl2+2rb

2mg+co2===2mgo+c

2mg+sio2===2mgo+si

mg+h2s===mgs+h2

mg+h2so4===mgso4+h2

2al+3cl2===2alcl3

4al+3o2===2al2o3 (passivation).

4al(hg)+3o2+2xh2o===2(4al+3mno2===2al2o3+3mn2al+cr2o3===al2o3+2cr2al+fe2o3===al2o3+2fe2al+3feo===al2o3+3fe

2al+6HCl===2ALCL3+3H22AL+3H2SO4===AL2(SO4)3+3H22AL+6H2SO4 (concentrated)===AL2(SO4)3+3SO2+6H2O

Al,Fe passivated in cold, concentrated H2SO4,Hno3) AL+4HNO(dilute)===AL(NO3)3+NO+2H2O2AL+2NaOH+2H2O====2Naalo2+3H22Fe+3BR2===2Febr3

fe+i2===fei2

fe+s===fes

3fe+4h2o(g)===fe3o4+4h2fe+2hcl===fecl2+h2

fe+cucl2===fecl2+cu

fe+sncl4===fecl2+sncl2

Fewer conditions, you need to know the quality of precipitation to seek.

Suppose the highest point is g and the platform is g

NaOH first neutralized hydrochloric acid, and 20 ml of NaOH was used to neutralize it. At this time, OH- and Mg2+ and Al3+ form precipitate, and at v=160 ml, Mg2+ and Al3+ are completely precipitated, but Al(OH)3 and OH- continue to produce ALO2-, and at v=180 ml, Al(OH)3 all generate ALO2-.

So the gprecipitate is mg(oh)2 and the amount of the substance molmg's mass =24* = g

The mass of Al(OH)3 = g, the amount of the substance mol

Mass of al =27* = g

HCl for reaction with metals

al --3cl-;Mg--2Cl- HCl(mol) for reaction with NaOH:

oh- -hcl

So 100 ml of hydrochloric acid solution has = mol HCl, and the amount concentration of the substance c = = 8 mol l

Answer: The mass of mg g, the mass of al g, the amount of hydrochloric acid concentration 8 mol l