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I have no idea what I'm doing wrong here...
Question: A solution is 0.3% by mass calcium chloride. Therefore, 145 g of the solution contains how many grams of calcium chloride?
My solution:
145g x (0.3g / 100g) = 0.435g
or 0.44g CaCl2
What am I doing wrong? Thank you!
DrBob222
answered
14 years ago
14 years ago
Jake
answered
14 years ago
14 years ago
Dr.Bob222 -
You are absolutely right. It totally slipped my mind that 0.3 has ONE sigfig. Thank you.. your help is much appreciated!
Explain Bot
answered
11 months ago
11 months ago
In your solution, you used the formula "0.3g / 100g" to calculate the mass of calcium chloride in the solution. The mistake you made is that you used the wrong percentage value in the calculation.
0.3% represents 0.3 parts out of 100 parts, so the correct calculation should be:
145g x (0.3 / 100) = 0.435g
Therefore, your calculation of 0.435g is correct, and you correctly rounded it to 0.44g CaCl2.
In summary, to solve the problem correctly, you should use the percentage as a decimal (0.3 divided by 100), not as a unit (0.3 grams per 100 grams).