What is the hole in the layer of ozone thought to have been caused by quizlet
When CFCs reach the stratosphere they are effected by ultraviolet radiation. This causes them to deteriorate and release chlorine atoms. These react with the ozone layer, causing chemical cycles of ozone depletion.
What is the ozone hole and what caused it?
Ozone loss occurs when the atmospheric levels of chlorofluorocarbons, (CFCs), and halons (gases that were once found in aerosol spray bottles and refrigerants) are released. (See details below).
Are CFCs still used in India?
Thanavat Junechaya, UNEP’s regional coordinator for its CFC Project, stated that India now produces nearly all of the CFC still being produced. However, the amount India exports is often lower than what is reported by other countries as being imported from India.
Is CFC-11 a greenhouse gas?
According to the NOAA Annual Greenhouse Gas Index (AGGI), the total radiative forcing by all long-lived greenhouse gases (carbon dioxide (CO2), methane (CO4), nitrous oxide (N2O), CFC-12, CFC-11, and various lesser gases) has increased by 26% since 1990.
What is used in aerosol spray?
The most commonly used propellants in the United States are naturally occurring hydrocarbons. A few products, about 10% of today’s aerosols, use compressed gases like carbon dioxide and nitrous oxide as propellants. The container is the final element. It is typically a steel or aluminium can.
What property of CFCs causes them to be useful?
Chlorofluorocarbons (CFCs) Their other important property is their volatility, having boiling points close to zero degrees Centigrade. These physical properties make them suitable for refrigerant gas use in refrigerators, freezers, and air conditioners.
Which refrigerants are flammable?
Refrigerants such as R410A, R407A and R404A are class 1 in their flammability, so do not show flame propagation when tested at 100 degC and 101.3 kPa in air. The flammability of class 2 refrigerants is lower than 0. 10 kg/m3 at 100degC and 101.3 kPa and a heat of combustion of less than 19 kJ/kg.
Which refrigerant blend is highly flammable?
Class 3 refrigerants have a high flammability level and a lower limit of flammability than or equal to 0. 00624 lb./cubic foot (0. 10 kg/cubic meter) at 14.6 psi and 70 degrees F, or a heat of combustion greater than or equal to 19 kilojoules/kilogram.
Is Freon 22 flammable?
Conditions to avoid : This substance is not flammable in air at temperatures up to 100 degC (212 degF) at atmospheric pressure. This substance should not be mixed with pressured air for leak testing, or any other purpose. Heat, flames, and sparks.
Why is R22 bad?
The main reason that the R22 refrigerant was banned is due to its effect on the ozone layer. Like all HCFCs, the R22 gas is an ozone-depleting substance which once released reacts with the ozone layer, causing significant damage.