Question

Question 2 What mass of K,CO3 is needed to prepare 200 mL of a solution having a potassium ion concentration of 0.150 M? 13.8 4.155 2.078 10.45 Previous

Answer 1

3) all these compounds are salt. Those salts are capable to form ions in water are soluble in water. And those not are insoluble.

Given values, volume of solution = 0.200 mL = 0.2L concentration of K+ = Grams of K2CO3 = ? 0.150 M Now, we knows Concentration No. of moles of solute Volume of solution in L No. of moles of conc. x volume of solution K2CO3 0. ISDMX 0.2 L Holes of K₂CO3 0.3 moll Now, we have molar mass of K2CO3 = 138.205 g/mol , no.of moles = 0.3 mo) Now Mass of Kz Coz moles X molar mass 0.3 mootx 138.205 g tool 4.146 Mass of K2CO3 < 4.15 g .. We need 4.15 g K2CO3 to make 200 ml solution.

So here , NH4Br , LiBr and RbBr are capable of forming ions in water so they are soluble in water.

But AgBr is not capable of forming ions , therefore this is insoluble in water.

So our answer is,

iv only