The average concentration of chloride ions (molar mass = 34.353) in seawater is 19.353 grams per kilogram. The maximum allowable concentration of chloride ion in drinking water is 250 ppm by mass. How many times as much chloride ion is there in seawater than the maximum amount allowed in safe drinking water?
How do I compare them? Would I convert them to moles? or can I compare them by mass?
I remember that 1 ppm = 1 mg/L and since 1L has a mass of 1000g (at least for dilute solutions) that will be 1 mg/kg.
You have 19.353g or 19353 mg/kg so you must have 19,353 ppm. You should be able to take it from here.
Let's see if that checks out.
? ppm = (g solute/g solvent)*1E6
?ppm = (19.353g/1000 g solvent)*1000 = 19353 ppm. Yep, it checks.
19,103
To compare the amount of chloride ions in seawater to the maximum permissible concentration in drinking water, it would be ideal to convert both quantities to the same unit. In this case, comparing them by mass would be appropriate.
To convert the concentration of chloride ions in seawater from grams per kilogram to ppm (parts per million), you can use the following example:
1 ppm = 1 mg/kg
Given that the average concentration of chloride ions in seawater is 19.353 grams per kilogram, you can convert it to ppm as follows:
19.353 grams per kilogram = 19.353 mg/kg
Now, let's compare this value to the maximum allowable concentration of chloride ions in drinking water, which is 250 ppm by mass. Since both values are now in ppm, you can directly compare them.
To find out how many times as much chloride ion there is in seawater compared to the maximum allowed amount in drinking water, simply divide the concentration of chloride ions in seawater by the maximum allowable concentration in drinking water:
(19.353 mg/kg) / (250 mg/kg) = 0.077412
Therefore, there is approximately 0.077412 times as much chloride ion in seawater compared to the maximum allowed amount in safe drinking water, or another way to express this is that the chloride ion concentration in seawater is about 7.74% of the maximum allowed concentration in drinking water.