Week 1 Question 6 Help Sapling

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Lilly Catarozoli 1B
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Joined: Wed Sep 30, 2020 9:53 pm

Week 1 Question 6 Help Sapling

Postby Lilly Catarozoli 1B » Fri Oct 09, 2020 1:24 pm

The question is, "If 3.88g of CuNO3 is dissolved in water to make a 0.880 M solution, what is the volume of the solution?". I converted the 3.88g to get moles and then used M=n/v and solved for v to get 0.02, but that answer is incorrect. Please help!

Thomas Vu 1A
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Re: Week 1 Question 6 Help Sapling

Postby Thomas Vu 1A » Fri Oct 09, 2020 1:31 pm

I think you have the equation for molarity wrong: its n = MV so V = n/M. You would then just substitute the values you found.

Connie Liang 3L
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Re: Week 1 Question 6 Help Sapling

Postby Connie Liang 3L » Fri Oct 09, 2020 1:56 pm

M = n/v is correct, but you can manipulate it to make finding the volume of the solution easier. So, you can multiply both sides by v and then divide both sides by M for v = n/M. You can then use the molar mass of CuNO3 to find the number of moles in 3.88 grams of CuNO3 which is .0309 moles. Now, you know the number of moles of solute (n) and the molarity of the solution (.88 moles/L) which was given. Therefore, you can use the v = n/M formula to find v, which is .0351 L. Hope that helped!

rhettfarmer-3H
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Re: Week 1 Question 6 Help Sapling

Postby rhettfarmer-3H » Fri Oct 09, 2020 1:59 pm

I just did the problem but yes i think you are on the right idea. Use the molar mass to be 125.556 g/mol. Convert from G to Moles. should get .03090255. Then from here we use M=n/v for our sake we need V=n/M. plugging in accordingly. we should
V=.03090255 (from conversion)/(.880)


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