To find high school chemistry answers, compulsory one. 46 pages.

It is recommended that you learn it steadily. I went online again and asked others about their own time. Think about it.

I have learned that the reaction of metals with acids and the reaction with salts are both displacement reactions. Reacts with alkaline elementals.

For example, mg and oxygen. This is called a chemical reaction (two elemental reactions to produce a substance). Oxidation Reaction Reduction Reaction. Think about it.

There's nothing to say about this question.,The most basic response must be remembered.。。 The main thing is that it's simple. It's much easier to memorize English words.

As for the 3rd. It's also easy to remember how many main clans he is, and if you think about it, you can write it out. It's really not difficult to remember this, just look at the gourd painting scoop. I really can't remember, turn to the last page and look at the periodic table...

These are basic things to remember. These are not difficult questions. I advise you to flip through the book more often, read carefully, and you will find that some questions will be done, and the most important thing is to memorize and then understand. Don't regret the time.

1.In the laboratory, sodium metal should be kept in kerosene. This is due to the fact that sodium reacts easily with air or water, and sodium is denser than kerosene, which sinks to the bottom of kerosene, and kerosene plays the role of isolating the air.

2na+o2na2o2 2na+2h2o=2naoh+h2↑ 7（1）3fe+4h2o（g）=fe3o4+4h2↑ （2）2al+6hcl=2a...

Page 81 Question 11:

Analysis: (1).

The ratio of the amount of the substance can be obtained according to the mass fraction of each oxide in which it is composed, and then the composition N(Na2O):N(CaO):N(SiO2)=13% 62:::1:6, then the composition is Na2O·Cao·6SiO2

2) Let the monthly mass of Na2CO3, CaCO3 and SiO2 be X, Y and Z respectively.

na2co3+caco3+6sio2==na2o·cao·6sio2+2co2↑

106g 100g 60*6g 478g

95%x 80%y 95%z 10t*31

106g/95%x=478g/31*10t x=

100g/80%y=478g/31*10t x=

60*6g/95%z=478g/31*10t x=

That is, the quality of Na2CO3, CaCO3 and SiO2 required per month is respectively.

Page 88 of 14:

1) (2) The main reason is that as the reflection progresses, MNO2 is gradually consumed, and when it is consumed to a certain extent, it is difficult to react again, so it has more mass than the theory.

Analysis: (1) Let the mass of the MnO2 solid be X

MNO2 + 4HCl (concentrated) ==== MnCl2 + Cl2 +2H2O (the reaction condition is heating).

87g 71g

x 4*100ml* -3

87g：x====71g：4*100ml* -3 x=

i.e. the mass of mno2 is required.

1、d2、b

3、b4、b

5. Solution, from 1mmol l=10 -3mol l, when the blood sugar macro value is, that is, the blood sugar value of the opening cover can also be known.

That is, so the normal blood sugar value of the person is in this range, so it is normal.

p561.(1) Chemical reactions, (2) Chemistry; Hot; The mutual transfer of chemical energy and electrical energy.

Change; Thermal energy is converted into chemical energy; Conversion of light energy into chemical energy; （3）①②2.(1) Wash and dry.

2) Crush the iron into iron filings, grind the sulfur into a fine powder, and mix it evenly and heat it.

Elicit a reaction. If the coal is not completely burned, it will not only waste energy, but also generate air pollutants such as CO and coal dust.

Lithium is a very reactive metal (2) and reacts easily with water (3).

Size, light weight, high voltage (up to above), high energy (output energy per unit mass or unit volume of the battery), long life (up to 5 to 10 years).

2。(1) When burning, silk has a smell, like the smell of burning hair, while cotton has no smell (2) Flame color reaction, sodium is yellow, potassium is light purple.

3) There are many methods, silver nitrate can be used, AGCL is white precipitate.

4) Add lime water directly. The precipitated is (NH4)2CO35The molar mass of sucrose is 12*12+1*22+16*11=342g mol

In this question, the converted mass concentration is: 342*. 137/。

This is a decimal number, so let's calculate it exactly.

3) Add Cu+ solution of copper sulfate to precipitate.

4) Add hydrochloric acid with gas into a clear lime solution white precipitate calcium carbonate first find the molecular weight of sucrose and then find how many moles of 137 grams and then divide the solution concentration 137 (12 * 12 + 22 + 16 * 11).

I add the first floor, and one is cotton with a burnt smell.

1. The atomic radius gradually decreases, the metallicity gradually decreases, and the non-metallicity gradually increases. The maximum atomic radius of this period is na; The most alkaline is Naoh; Al(OH)3 is amphoteric and hclo4 is the most acidic.

8.(1) x is c y is o z:na w is al2) there are 2 elements in the first period, and there are 8 elements in the second and third periods, and the atomic number increases at one time.

3) You wrote this yourself about the combustion reaction. Mountain hunger.

Solution: mg---h2 al---3 2h2m 24 m 24 m 27 m 18 m 24 > m 18 so the mass of magnesium reacts with a sufficient amount of acid to form h2 mg the mass of aluminum, so the mass of magnesium reacts with a sufficient amount of acid to form h2 at the same volume, and the mass magnesium is more.