Answer to Question #32915 in Inorganic Chemistry for Joy
1.61 grams of an hydrated salt BxH2O gave 0.714 grams of the an hydrous salt when heated. What will be the value of x if the relative molecular mass of B is 142?
An hydrous salt is B. If m(B) = 0.714 grams M(B) = 142 g/mol So, n(B) = m/M n(B) = 0.714 g / 142g/mol = 0.005 mol; We see, that n(B) : n(BxH2O) = 1 : 1; So, n(BxH2O) = 0.005 mol; m(BxH2O) = 1.61 grams By the formula M = m/n we can find the molecular mass of an hydrated salt M(BxH2O) = 1.61 g / 0.005 mol = 322 g/mol M(xH2O) = M(BxH2O) - M(B); M(xH2O) = 322 g/mol - 142 g/mol = 180 g/mol if M(H2O) = 18 g/mol x = M(xH2O) / M(H2O) x = 180 / 18 = 10 Answer: x = 10