Why is the pH of acid rain set at 5 6

Due to the pollution of the atmosphere, acid rain zones began to form in some areas. The acid rain areas in China are mainly distributed in the south of the Yangtze River, the east of the Qinghai-Tibet Plateau and the Sichuan Basin. Acid rain pollution is the most severe in central China, and the average annual pH value of acid rain in the central region is lower than 80, and the frequency of acid rain is above 80.

The acid rain area in southwest China, centered on Nanchong, Yibin, Chongqing and Zunyi, has been slowing down in recent years, but it is second only to central China, with a low annual average pH and a frequency of acid rain higher than 80. Acid rain in the coastal areas of East China is mainly distributed in the coastal areas from the south of the lower reaches of the Yangtze River to Xiamen, and the intensity of acid rain pollution in this region is weaker than that in central and southwest China, but the regional distribution is wider, covering southern Jiangsu, southern Anhui, most of Zhejiang and the coastal areas of Fujian. Acid rain in South China is mainly distributed in the Pearl River Delta and the eastern part of Guangxi, and the average annual pH value of precipitation in heavily polluted cities is in the range, and the frequency of acid rain in the central region is in the range of 60 90.

Acid rain pollution is more common in Guangxi, except for the southern coastal area, the frequency of acid rain in most areas is above 30, and the acid rain area extends to the east and west along the Hunan and Guizhou corridors, and is connected to the Pearl River Delta in the east.

Carbon dioxide dissolves in water to form carbonic acid, which makes rainwater slightly acidic.

Rain contains some acidic substances.

If the pH value is less than that, it is acid rain, and if it is less than it, it is heavy acid rain.

Acid rain refers to atmospheric precipitation (fog, frost) formed by rain, snow or other means with a pH value of less than that. In a broad sense, it refers to the dry and wet sedimentation of acidic substances. Acid rain is mainly composed of acid gases such as sulfur dioxide and nitrogen oxides produced by the combustion of fossil fuels, which are absorbed and dissolved by rainwater through complex atmospheric chemical reactions.

Its acidic components are mainly sulfuric acid, but also nitric acid and hydrochloric acid.

Acid rain in China is mainly formed by the burning of coal with high sulfur content, mostly sulfuric acid rain, less nitric acid rain, and in addition, the exhaust emissions of various motor vehicles are also an important cause of acid rain. The scientific standards for defining acid rain areas in China are still being discussed, but it is generally believed that the average annual precipitation pH is higher than that and the acid rain rate is 0-20%, which is a non-acid rain area; The pH is between the levels, and the vertical rate of acid rain is 10-40%, which is a light acid rain area; pH between, the acid rain rate is 30-60%, which is a moderate acid rain area; The pH is between 50-80%, which is a heavier acid rain area. The pH is less than that, and the acid rain rate is 70-100%, which is a heavy acid rain area.

pHLess than is heavierAcid rainzone, between the pH value is acid rain.

Acid rain refers to atmospheric precipitation with a pH value lower than that, including rain, snow, graupel, hail, dew, and frost, and the pH value is less than 70 100%, which is a heavy acid rain area.

The pH of acid rain is generally less than.

Acid rain is when rain, snow, etc. absorb and dissolve sulfur dioxide and nitrogen oxides in the air during the formation and landing.

and other substances, with the acidic precipitation formed by the rubber grip with a pH lower than that, most of the acid rain is mainly caused by man-made emissions of a large number of acidic substances into the atmosphere, so Peiqing usually tries to travel with low carbon and protect the environment.

The pH of acid rain is generally less than. Acid rain is rain, snow and other substances in the formation and landing process to absorb and dissolve sulfur dioxide, nitrogen oxides and other substances in the air, the formation of pH below the acid precipitation, now most of the acid rain is mainly caused by man-made emissions of a large number of acidic substances into the atmosphere, so we usually try to low-carbon travel to protect the environment.

What is the pH range of acid rain.

Acid rain refers to rain, snow, or other forms of precipitation with a pH value of less. Acidic precipitation with a pH value lower than that of rain and snow absorbs and dissolves sulfur dioxide, nitrogen oxides, and other substances in the air during the formation and fall.

Formation of acid rain

In addition to the naturally occurring acid rain, most of the acid rain is mainly caused by the artificial emission of a large number of acidic substances into the atmosphere, such as the combustion of a large amount of high sulfur content of the Fanli coal, which will form sulfuric acid rain, and a small part will form nitric acid rain. In addition, the exhaust fumes emitted by motor vehicles are also one of the important reasons for the formation of acid slippery rain.

Hazards of acid rain

Acid rain will cause great harm to our daily life, will lead to soil acidification, induce plant pests and diseases, inhibit the reproduction of soil microorganisms, affect the urban landscape, and damage the environment, so we must prevent acid rain, drive less in our daily life, ride more bicycles, use clean energy such as natural gas, protect the environment, and start from ourselves and our surroundings.

The standard stipulates that acid rain is atmospheric precipitation with precipitation less than pH, and acid rain areas are areas with average precipitation pH less than that.

The rain with a pH less than is acid rain, and the stool is in the shape of acid rain.

Combustion of fossil fuels, vehicle exhaust, etc.

At the International Conference on the Environment in June 1982, the National Conference on the Environment.

For the first time, the pH value will be less than the drop.

Water (including rain, snow, frost, fog, hail, graupel.

etc.) officially designated as acid rain. From the perspective of standardizing the observation and service business of acid rain in the meteorological industry, this paper refers to the common habitual classification methods of acid rain pollution degree at home and abroad, and combines the statistical analysis of acid rain observation data, business product production and technology development experience of China Meteorological Administration, and proposes the classification index system of acid rain, acid rain frequency and acid rain area grade.

The standard stipulates that acid rain is atmospheric precipitation with precipitation less than pH, and acid rain areas are areas with average precipitation pH less than that. According to the pH value of precipitation on a simple closed day, acid rain was divided into weak acid rain, weak acid rain, strong acid rain and extremely strong acid rain. According to the frequency of acid rain in a certain period of time (monthly, quarterly and yearly) at a single station, the frequency of acid rain is divided into occasional acid rain, less acid rain, more frequent acid rain and high acid rain frequency. The spatial distribution of the average precipitation pH value (monthly, quarterly, and annual) was calculated by interpolation method from the pH value of all single stations (monthly, quarterly, and annual) in the region, and the acid rain area was divided into light acid rain area, light acid rain area, heavy acid rain area, and extremely heavy acid rain area. <>

1. Acid rain refers to rain and snow with a pH less than or other forms of precipitation. During the formation and fall of rain and snow, sulfur dioxide, nitrogen oxides and other substances in the air are absorbed and dissolved, forming acidic precipitation with a pH lower than that.

2. Usually the pH value is a number between 0 and 14 (the pH of sulfuric acid is about -2), at a temperature of 25, when pH 7, the solution is alkaline, and when pH = 7, the solution is neutral.

3. However, under hail conditions such as non-aqueous solution or non-standard temperature and pressure, pH=7 may not mean that the solution is neutral, which needs to determine the value of pH neutral by calculating the ionization constant of the solvent under such conditions.