Answer: hydroxide ions
Explanation:
According to the Arrhenius concept, an acid is a substance that ionizes in the water to give hydronium ion or hydrogen ion and a bases is a substance that ionizes in the water to give hydroxide ion .
According to the Bronsted Lowry conjugate acid-base theory, an acid is defined as a substance which donates protons and a base is defined as a substance which accepts protons.
According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs.
As KOH can give hydroxide ions on dissociation , it is considered as arrhenius base.

Answer:
The solvent is the substance that dissolves solutes.
Explanation:
Solutes are the ones being dissolved. Examples could be sugar, salt, etc.
Solvents are the dissolver. Examples could be acids like HCl or water.
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Answer:
MSDS -- Material Safety Data sheet
Explanation:
The full form of MSDS is Material Safety Data sheet. A Material Safety Data Sheet is a document which contains the information related to the potential hazards (fire or reactivity and environmental and health ) and includes how to work or use the chemical product safely.
It is regarded as an essential starting point for development of the complete health as well as safety program. MSDS also contains other information such as the use of the chemical, its storage and also handling and the emergency procedures that are related to the hazards of the material.