<u>Answer:</u> The mass of arsenic found in the sample is 0.25 mg
<u>Explanation:</u>
ppm is the amount of solute (in milligrams) present in kilogram of a solvent. It is also known as parts-per million.
To calculate the ppm of oxygen in sea water, we use the equation:

Both the masses are in grams.
We are given:
Concentration of arsenic = 5 ppm
Mass of sample = 50 g
Putting values in above equation, we get:

<u>Conversion factor used:</u> 1 g = 1000 mg
Hence, the mass of arsenic found in the sample is 0.25 mg
Answer: D, splitting water into hydrogen and oxygen is a chemical change.
Decreasing the turns of wire
It becomes a liquid with the water
Answer: The pH of the solution is 11.2
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

where,
n = moles of solute
= volume of solution in ml
moles of
=
(1g=1000mg)
Now put all the given values in the formula of molality, we get


pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
![pOH=-\log [OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%20%5BOH%5E-%5D)

According to stoichiometry,
1 mole of
gives 2 mole of
Thus 0.0298 moles of
gives =
moles of
Putting in the values:
![pOH=-\log[0.0596]=2.82](https://tex.z-dn.net/?f=pOH%3D-%5Clog%5B0.0596%5D%3D2.82)



Thus the pH of the solution is 11.2