What mass of Ca(OH)2 is required to prepare 200mL of 0.2N solution? (Relative atomic mass are Ca=40smu , H=1amu , O=16amu)

What mass of K3PO4 is required to prepare 400mL solution that contains 6 x 10^21 K3PO4 particles per liter of solution?  ( atomic masses are  K=39amu, P=31amu  O=16amu)

Z is a 0.1 M solution of malic acid, C4H605 in water

(Relative atomic mass: C 12; O 16; H 1).

(a) Show how you would prepare 1 dm3 of solution Z.

(b) Show the relationship between the number of moles of malic acid and its molar concentration.

131. Naturally occurring magnesium has an atomic mass of 24.312 and consists of three isotopes. The major isotope is 24Mg, natu- ral abundance 78.99%, relative atomic mass 23.98504. The next most abundant isotope is 26Mg, relative atomic mass 25.98259. The third most abundant isotope is 25mg, whose natural abun dance is in the ratio of 0.9083 to that of 26Mg. Find the relative atomic mass of 25Mg.