The concentration of the solution is also known as Molarity (M). The formula for molarity is
M = mol / liters
We already have the liters, so we only need to find moles. We can find the number of moles by using the molar mass of NaCl and the given amount. That can be found using the elements' atomic weights given on the periodic table.
22.990 (mass of Na) + 35.453 (mass of Chlorine) = 58.443 g / mol
That's how many grams are in one mole of NaCl, but we only have 2.5 grams. So, let's divide and see how many moles we have.
2.5 / 58.443 = .042776 moles
Now we can plug our numbers into the formula.


M = .02138 mols/L
So, your concentration is about .02 mol/L.
The OSHA limit for STEL-TWA is 2ppm and the PEL-STEL value is 4ppm to the exposure to nitric acid.
OSHA refers to Occupational Safety and Health Administration has adopted standard values for the exposure to harmful and hazardous chemicals so that the safety of workers and testing animals could be ensured.
Here, STEL-TWA stands for Short Term Exposure Limit - Time-Weighted average, and PEL-STEL stands for Permissible Exposure Limit- Short Term Exposure Limit.
This is usually set up in industries to ensure the safety of the workers and the maximum exposure short-term time limit is 15min and 2ppm for STEL-TWA and 4 ppm for PEL-STEL.
To know more about Industrial Safety measures, click below:
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Answer: -
5 : 1 : 3
Explanation: -
Mass of CO₂ = 2.2 g
Molar mass of CO₂ = 44 g / mol
Number of moles of CO₂ = 
= 
= 0.05 mol
Number of atoms of nitrogen = 6.02 x 10²¹
Number of moles of nitrogen = 
= 
= 0.01 mol
0.03 gram atom of sulphur means 0.03 moles of sulphur.
Thus the mole ratio of CO₂ : N : S = 0.05 : 0.01 : 0.03
= 5 : 1 : 3
<span>As mentioned, the isomerization of cyclopropane to propylene is a first-order process with a half-life of 19 min at 500°c. A first-order reaction kinetic rates means that the rate is constant throughout the reaction.
Thus, the time it takes for the partial pressure of cyclopropane to decrease from 1 atm to 0.125 atm at 500°c is </span><span>57 minutes.</span>
It all depends on if you know the mass number and atomic number then you will be able to find out what the amount of neutron in an element.