DAT bootcamp GC Test 4 quesition help

[dental deezle]

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11. What is the mass percent of methanol in a solution prepared by diluting 16 grams of methanol with 32 grams of water?

The answer says mass percent = g of solute/g of solution which is 16/48 x100 but I thought mass percent/percent composistion was an intrinsic factor, and you only calculate it with the mass of the element/mass of the compound which would be CH4= 16 H2O =18


so grams CH4/G CH4 + H2O = 16g/34g x 100 = about ... 50% Why am I wrong?

 

[THAPA]

I think it should be % mass= mass of methanol/total mass X 100 %= 16/48 X 100= 33.3 %

What is the answer?

 

[dental deezle]

H

I think it should be % mass= mass of methanol/total mass X 100 %= 16/48 X 100= 33.3 %

What is the answer?

ya but I though mass percent was an intrinsic calculation where you don't need the info in the question to get the answer. Is mass percent and percent composistion the same?

 

[tommyngu]

11. What is the mass percent of methanol in a solution prepared by diluting 16 grams of methanol with 32 grams of water?

The answer says mass percent = g of solute/g of solution which is 16/48 x100 but I thought mass percent/percent composistion was an intrinsic factor, and you only calculate it with the mass of the element/mass of the compound which would be CH4= 16 H2O =18


so grams CH4/G CH4 + H2O = 16g/34g x 100 = about ... 50% Why am I wrong?

It's best not to take the definition of "mass percent" as "mass percent of element X in compound XYZ." Your issue sounds like a case of thinking too much into the question. This question specifically asks for the mass percent of methanol in the solution so you would find the proportion of methanol as a mass and divide it by the total mass of the solution multiplied by 100%.