Avogadro's constant is a frequent visitor to the college entrance examination, and since it is a regular student, then we have no reason to lose points. Take the 2023 Fujian College Entrance Examination as an example:
a.Find the number of protons of the particles.
Unless otherwise specified, the number of protons of a particle is equal to the atomic number.
Here n is 7, o is 8, and h is 1, i.e. 7+8+4=19
b.To find the number of ions, including anions and cations, we must first calculate how many mols there are in the substance, that is, 48g (14*2+16*4+1*4g) mol=05mol, so the number of anions and anions is 1na
c.What is a key.
Methods for judging bonds and bonds in molecules.
1) If a bonded atom has only one common electron pair, the covalent bond must be a bond; If more than one shared electron pair is formed, one bond is formed first, and the other atomic orbitals form bonds.
2) General rule: A covalent single bond is a bond; There is one covalent double bond and the other is a bond; One of the covalent triple bonds is a bond and the other two are bonds.
There are four N-O single bonds here.
Generally, 224L is 1mol, 112l is 05mol。According to the chemical equation 05mol of hydroxylamine nitrate can only produce 005mol nitrogen and 1mol water.
Why the emphasis on generally?
Because SO3 is a liquid at room temperature, the standard condition is solid.
Neopentane is a gas at room temperature and liquid at standard temperature.
HF is a gas at room temperature and liquid at standard temperature.
no The normal temperature is a gas, and the standard condition is a liquid.
In cases like this, we can't use it under the standard condition, because the molar volume of a gas refers to the gas, and under the standard condition, these gases become non-gases.
A common test for the NA value of Avogadro's constant.
1.The number of molecules, the number of atoms, the number of ions, the number of protons, the number of neutrons, the number of electrons, ......
2.Polar bonds, non-polar bonds, bonds, bonds, ......
3.The number of electrons transferred in the redox reaction, whether the substances involved are hydrolyzed, and the structure of organic matter (number of functional groups, etc.).
Take the 2023 Zhejiang College Entrance Examination as an example.
Based on the answer template above, we can solve this problem.
a.Why did he use the word the most? Because C2H4O has two possible energies, i.e., there is a functional group-cho, in this case, it has one less key and one more key.
b.Calculate how many mols H2O2 has and multiply it by the number of oxygen atoms, i.e. 17g (2*1+16*2g)mol=0.05mol
c.Let's not talk about ammonium ions, let's talk about whether it undergoes a redox reaction to transfer the number of electrons, whether the substance is hydrolyzed, and one of the organic structures (number of functional groups, etc.), that is, a hydrolysis reaction occurs, like this case, the ammonium ion is not a definite number.
d.The answer can be obtained from the same reasons as above.
Let's take the 2023 Guangdong College Entrance Examination as an example.
The template above can be used to solve mental arithmetic problems, such as bicarbonate ions, which are hydrolyzed and ionized, so their number is not a definite number.
Disclaimer: Created by middle school students for communication purposes only and not as a theoretical basis for learning.