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Hand warmers are small (sometimes disposable) packets which are held in the hand and produce heat on demand to warm cold hands. They are commonly used in outdoor activities such as hiking and skiing to keep the extremities warm and assist insulated clothing. Other types of warmers are available to provide soothing heat for muscular or joint aches. Some hand warmers contain cellulose, iron, water, activated carbon, vermiculite and salt and produce heat from the exothermic oxidisation of iron when exposed to air. A second type generate heat through exothermic crystallisation of supercooled molten materials (usually sodium acetate) and are reusable. These can be recharged by boiling the warmers and allowing them to cool. Heating of the pads is triggered by snapping a small metal device buried in the pad which generates shock waves to initiate crystallisation. A third type uses lighter fluid (lighter fuel) or LPG which is reacted with a platinum catalyst to release heat by oxidation reactions. These can be used on many occasions by simply refuelling. Depending on the type and the source of heat, hand warmers last between 30 minutes (recrystallisation) though to 12 - 24 hours.
Hand warmers typically contain iron powder, salt, activated carbon, vermiculite, and water. The reaction involves iron oxidation (rusting) in the presence of oxygen, which is exothermic, producing heat. The salt acts as a catalyst to speed up the reaction.
Some hand warmers contain cellulose, iron, water, activated carbon (to speed up reaction), vermiculite (water reservoir) and salt (catalyst) and produce heat from the exothermic oxidation of iron when exposed to air.
you push the button witch releses a liquid and it forms a chemical reaction and makes it heat. and its not to pick noses for whatever stupid brainless person put that.
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The change that takes place when two or more substances interact to form new substances is called a reaction.?
two
What occurs when a chemical reacion takes place?
During a chemical reaction, chemical bonds are broken and formed between molecules, resulting in the transformation of reactant substances into products. Energy is usually absorbed or released during this process, leading to changes in the properties and composition of the substances involved. The chemical reaction is governed by the principles of conservation of mass and energy.
Is physical or chemical reaction takes place when sodium hydroxide mixed with water?
When sodium hydroxide is mixed with water, a chemical reaction takes place where the sodium hydroxide dissociates into its ions, Na+ and OH-. This is a physical change.
Were chemcal reaction takes place cell organelles?
Chemical reactions take place in various cell organelles. For example, in mitochondria, reactions like cellular respiration occur to produce energy. In the nucleus, reactions like DNA replication and transcription occur. And in the cytoplasm, reactions like protein synthesis take place.
What is the opposite of reactants?
The opposite of reactants would be products. Reactants are the substances that are present before a chemical reaction occurs, while products are the substances that are formed as a result of the reaction.
Which part of an atom or ion takes part in a chemical reaction?
The valence electrons are the part that takes place in a chemical reaction.
What type of reaction take place in rancidity?
chemical reaction takes place in rancidity
What do you call the substances before a chemical reaction takes place?
These initial substances are the reactants.
What chemical reaction takes place in respiration?
NaHCO3
What is the name for the chemical that takes place in a reaction?
reactant
When a chemical reaction takes place the compound formed is called the?
When a chemical reaction takes place, the compound formed is called the product. The product is the end result of the chemical reaction, typically formed from the reactants that underwent a rearrangement of atoms.
What chemical reaction takes place when an iron nail rusts?
Rusting is an oxydation reaction.
Does volume not change when a chemical reaction takes place?
The volume is changed.
What is broken down before a chemical reaction takes place?
bonds
Is energy always given out when a chemical reaction takes place?
Yes.
What is substance that takes place in a chemical reaction?
These substances are called reactants.
Can a chemical reaction takes place in which energy is neither absorbed released?
no
