You forgot to include the known characteristics of the solution.
I searched them and copy here:
volume: 1.000 liter
M = 0.0190 M
Now, you can start with the definition of mass percent.
mass percent = (grams of solute / grams of solution) * 100
grams of solute are obtained from the molar concentration:
M = (number of moles of solute) / (volume of solution in liters)
where number of moles = (grams) / (molar mass)
=> M = (grams of solute / molar mass of solute) / (volume of solution in liters)
=> grams of solute = M * (volume of solution in liters) * (molar mass of solute)
And density = (kg of solution / volume of solution in liters) =>
kg of solution = density * volume of solution in liters
grams of solution = density * (volume of solution in liters) * 1000 g/kg
=> mass percent = M * (volume of solution in liters) * (molar mass) / (density * volume of solution in liters * 1000 g/ kg) * 100
=> mass percent = M * molar mass * 10 / density
now replace the values known:
M = 0.0190 mol / liter
density = 1,000 kg / liter
molar mass of Ba(NO3)2 = 137.327 g/mol + 2*14.007 g/mol + 2*3*15.999 g/mol = 256.335 g/mol
=> mass percent = 0.0190 mol/liter * 256.335 g/mol * 10 kg/ g / (1.000 kg/liter)
=> mass percent = 48.7%
The answer is I
The correct way of writing this would be silver(I) sulfide, but silver sulfide without the (I) is also OK because it isn't always writte, nor is it necessary to write the (I).
The correct option is B.
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