Answer:
The 8-hour TWA exposure for the employee is 101 ppm and it exceeds the OSHA PEL of 100 ppm for ethylbenzene.
Explanation:
The TWA for 8 hours is calculated by the sum of airbone concentrations multiplied by the time it has been exposed to that period. The total is divided by 8 which refers to the 8 hours total the employee has been exposed.
TWA = (125x2+88x2+112x2.5+70x1.5)/8.
The OSHA PEL is a known number for every compound and it can be find in PEL tables. In the case of ethylbenezene, it is 100 ppm.
What minerals do rocks have?
Do all rocks have minerals?
What is the hardest mineral?
Answer:
OH⁻
Explanation:
A base is defined as a substance which interacts with water to yield excess hydroxide ions, OH⁻, in an aqeous solution.
Examples are Sodium hydroxide (NaOH)
Potassium hydroxide (KOH)
Bases are generally certain metallic oxides, metallic hydroxides and aqueous ammonia.
An acid is a proton donor, H⁺ and it interacts with water to produce excess hydroxonium ions in an aqueous solution.
Oxidation-reactions are equations where some species release electrons and other species gain electron.
So two reactions happen simultaneously the oxidation of one species and the reduction off the other species.
In the oxidations, the species release electrons and, consequently, increase their oxidation number.
In the reductions, the species gain electrons and, consequently, decrease their oxidation number.
This last reaction, reduction, is what the above equation represents: Sn 4+ is gaining 2 electrons and so its oxidation number decrease from 4+ to 2+.
In, conclusion that is a reduction equation (option d)
