You're going to divide the mass of chlorine within the compound by the mass of the compound, and then multiply the result by 100 to get the answer
<u>Answer:</u> The longest wavelength of light is 656.5 nm
<u>Explanation:</u>
For the longest wavelength, the transition should be from n to n+1, where: n = lower energy level
To calculate the wavelength of light, we use Rydberg's Equation:

Where,
= Wavelength of radiation
= Rydberg's Constant = 
= Higher energy level = 
= Lower energy level = 2 (Balmer series)
Putting the values in above equation, we get:

Converting this into nanometers, we use the conversion factor:

So, 
Hence, the longest wavelength of light is 656.5 nm
This problem is providing the mass-volume percent of a formic acid solution so its molarity is required and found to be 0.313 M after the following calculations.
<h3>Molarity</h3>
In chemistry, units of concentration provide a measurable understanding of the relationship between the relative amounts of both solute and solvent. In the case of molarity, one must relate moles of solute and liters of solution as follows:

In such a way, when given this mass-volume percent of 1.44% for the formic acid in the solution, one can assume there is 100 mL of solution and 1.44 g of solute (formic acid), which means one must convert the volume to liters and the mass to moles with:

Finally, we plug in these numbers in the equation for the calculation of molarity:

Learn more about molarity: brainly.com/question/10053901
Answer: its 15 its none of those
Explanation:
Answer: The pressure will be 18.05 atm.
Explanation: Expression for ideal gas equation is :

where,
P = Pressure of the gas = ? atm
V = Volume of the gas = 0.333L
n = Number of moles of gas = 0.250 moles
R = Universal gas constant = 
T = temperature of the gas = 20°C = (273 + 20)K = 293K
Putting values in above equation, we get:

P = 18.05 atm