Lily F.
asked • 01/31/21If one mole of a substance has a mass of 32.0 g, how many moles are in 0.45 kg of the substance? Express your answer in moles using the correct number of significant figures.
If one mole of a substance has a mass of 32.0 g, how many moles are in 0.45 kg of the substance? Express your answer in moles using the correct number of significant figures. Do not enter your answer using scientific notation.
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1 Expert Answer
J.R. S. answered • 02/01/21
Tutor
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Ph.D. University Professor with 10+ years Tutoring Experience
Use dimensional analysis:
0.45 kg x 1000 g / kg x 1 mole / 32.0 g = 14.06 moles = 14.1 moles (3 sig. figs.)
(Note how kg and g cancel leaving moles)
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Alex O.
Im leaving this as a comment rather than an answer. First let's get everything in the same unit, so let's first convert our 0.45 kg into grams before we set up a proportion. So, 0.45 kg is equal to 450 g. Next we can set up the proportion: (1mol/xmol)=(32.0g/450g). Solve of proportion for X. Do this by cross multiplying to write an equation 32.0X = 450 then solve for X. I got X = 14.1mols, let me know what you get. ******Remember, I am not responsible if your work submission is incorrect. I am not entirely sure if my calculations or processes are always correct!******01/31/21