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The standard state refers to a state of standard pressure (usually one standard atmosphere), which indicates the temperature of the standard state. In fact, this sentence can be removed!

The so-called standard state is the state of the substance at a specified temperature t and standard pressure p, referred to as the standard state.

The standard state does not specify the temperature, and usually uses a value that can be approximated as 298 k), so it is not necessary to indicate it. If it is a different temperature, the temperature value should be marked in the lower right corner.

Be careful to distinguish between standard status and standard status.

The standard condition specifies the temperature and pressure, 0 (k kpa, while the standard state is different, the standard state of a pure ideal gas is the state in which the gas is at a standard pressure p (100 kpa); [1] The standard state of mixed ideal gas refers to the state in which the partial pressure of any gas component is p; The standard state of a pure liquid (or pure solid) substance is a pure liquid (or pure solid) at a standard pressure p.

The standard state specifies only the pressure p, but not the temperature, so the standard state of the temperature-dependent state function should indicate the temperature.

It should be noted that since the standard state specifies only the pressure p, but not the temperature, the standard state of the temperature-dependent state function should indicate the temperature. For ease of comparison, the International Union of Pure and Applied Chemistry (IUPAC) recommends k(0) as the reference temperature. It is important to note that prior to 1982, IUPAC used to be the standard state of pressure.

When consulting thermodynamic data from manuals or monographs, attention should be paid to the standard status specified in the manual or monograph to avoid misuse of the data.

Standard state of matter:

Pure gas at standard pressure (p = 100kpa).

Pure liquids and pure solids at standard pressure (p = 100kpa).

The molar concentration of solute in solution is 1mol·kg-1 (approximate 1mol·l-1) at standard pressure (p).

In thermodynamics, the general standard state only stipulates 1 atmosphere, not the temperature, and the standard state is included in the decision of the International Conference on Weights and Measures.

The standard is at one atmosphere.

553018430 No, oxide glass is divided into silicate glass, borate glass, phosphate glass, etc. Silicate glass refers to glass with the basic composition of SiO2.

It is not possible to react without strong acid to make weak acid.

by calcium hydroxide solution.

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These are the basic questions.

Categorize it several times when understanding.

A systematic summary.

None of the above questions are a problem.

The chemical formula of R atoms to form ionic compounds is AMRN, which means that R is a negative ion in this compound, and the valency is -m, that is, each atom gets m electrons, and the number of electrons of one of its atoms is a-m, and the number of protons is also a-m. The number of neutrons in the nucleus is b, and its mass number is a-m+b. So his elemental notation should be written.

The sum of the total number of electrons outside the nucleus of x r is (74-6)=68

The total number of outermost electrons outside the nucleus of x r nucleus is (32-4)=28, the outermost electrons are 8, and the outermost 7 electrons are introduced 4*7=28, x=4, r atomic number=68 4=17, and r is cl

In summary, r=cl, x=4

Hello: Let the molecular formula of the hydride be nxhy

From the inscription, [the relative molecular mass is" 14x+1y=[the mass fraction of the nitrogen atom is》14x

Solution x 3, y 1

So the molecular formula of this hydride is N3H

This hydride is completely decomposed into nitrogen and hydrogen when impacted, which can be converted into the following chemical equation:

2n3h = impact = 3n2 + h2

From this, it can be obtained that the amount of matter of the gas formed after the reaction is twice the amount of the substance of the reactant, i.e.

n(n2+h2)=2n(n3h)

Because the amount of the hydride substance is.

So the volume of the gas produced v (total) =

Done, got it?

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The number of protons in the nucleus is 5, and it has neutron numbers of 5 and 6 in nature.

It shows that the relative atomic masses of the two isotopes differ by 5+5 = 10 and 5+6 = 11

According to the crossover method of the Ten Xiang manuscripts, the ratio of the number of these two isotopes in nature = 11 - 10) = 1:4

So the ratio of numbers in nature = 1:4

The atomic mass = the number of protons + the number of neutrons.

So the relative atomic masses of the two isotopes are 10 and 11

Cross: The number of neutrons is 5 and 6, and the ratio of the number of two isotopes = (brother in the row: (:4

The number of protons is 5 and the element is b

10b 11b (numbers are superscript).

Let the 10b contained in the sedan car source be x, then the 11b contained is 1-x10x+11(1-x)=

x=x=The ratio of the two isotopes to the number of closed brightness in nature is: 4

Ion A (m- in the upper right corner) means that atom A gets m electrons, and if there are x electrons outside the nucleus, the number of protons is x-m

The mass number is the number of protons + the number of neutrons = x-m + n

The number of protons is x-m

The mass number is x+m+n