Calculate the mass of copper sulfate (CuSO4.5H2O) required to prepare 250 mL solution of 1000 mg Cu L-1.?

How do u do this type of question. Thanks

3 Answers

  • 1 decade ago
    Favorite Answer

    Break the problem down into two parts, working backwards:

    We need enough copper (as CuSO4.5H2O) to make 250 mL of a solution which contains 1000 mg of copper per litre. 250 mL is a quarter of a litre, so we need (1/4) x 1000 = 250 mg of copper.

    The problem then is that copper sulphate contains other components beside copper, so how do we work out how much we need to get 250 mg of copper. If you are familiar with the concept of 'moles', it's reasonably easy.

    The molar mass (or atomic weight) of copper is 63.546, so that 250 mg of copper is 250 x 10^-3/63,546 = 3.934 x 10^-3 moles. Since there is one atom of copper in each molecule of copper sulphate, this means that we need the same number of moles of that compound to ensure that we have 250 mg of copper.

    The molar mass of copper sulphate is obtained by adding up the combined atomic weights of all the atoms present in the compound (1 x Cu, 1 x S, 9 x O and 10 x H) ie

    Molar mass CuSO4.5H2O = 63.546 + 32.065 + 9 x 15.999 + 10 x 1.008 = 249.682 g

    So 1 mole of copper sulphate weighs 249.682 grams; 3.934 x 10^-3 moles will weigh 3.934 x 10^-3 x 249.682 = 0.982 g.

    Hence we need 0.982 g of copper sulphate to prepare 250 mL of the specified solution.

    (If you're not familiar with moles, let me know and I'll rewrite it simply in terms of proportions.)

  • ?
    Lv 6
    1 decade ago

    1000 mg/l. You need a quarter liter, so take 250 mg of sulfate and fill up with water to 250 ml.

  • ?
    Lv 4
    4 years ago

    very few must have examine this questions and extremely few responded it in spite of the actuality that i'm also between them a citizen of u . s . of america previously an Indian as we received't stay a citizen of two international places because being American resident we are no better Indian yet we are able to visit our mom land for ever and are free to stay there too loosing all advantages if we stay longer i imagine , each and all of us loves peace and hate an section the position there is no safe practices . when I see terrorism is a international situation each and all of us ought to play his or her position . at the same time as Malala a muslim lady can wrestle for education of girls ,at the same time as a baby needs his or her freedom a terrorist lives in terror and not in any respect free from its consequences ,an afternoon might want to come at the same time as human beings might want to come ahead to wipe it from human minds even though it truly is in simple terms too late already , there are such countless technique of destruction to wipe total humanity if needed action isn't taken faster . i'm too small to take any action ,yet all type of violent videos must be removed from media so as that we do no longer have get suitable of entry to to them by ability of any ability . human beings can lease a majority of those videos for couple greenbacks and stand as a lot as wrestle with kinfolk then to next neighbor then at artwork then someplace at paying for mall ,then anyplace he does no longer imagine suitable led to by technique of media and elements he can get suitable of entry to from cafes and fashionable human being dollar who supply this freedom so incredibly . Then we attempt to calm the ideas it is already bombarded with a lot detrimental information international huge .

Still have questions? Get your answers by asking now.