Which solution contains the smallest number of moles of sucrose (c12h22o11, molar mass = 342.30 g/mol)? 2,000 ml of a 5.0 × 10–5% (w/v) sucrose solution 20 ml of a 5.0 m sucrose solution all of the solutions contain the same number of moles of sucrose. 2,000 ml of a 5.0 ppm sucrose solution?

> 2,000 mL of a 5.0 × 10–5% (w/v) sucrose solution 

5.0 × 10–3 g/mL * 2000 mL * (1 mol / 342.30 g) = 0.0292 mol

> 2,000 mL of a 5.0 ppm sucrose solution

5 grams / 1000000 mL * 2000 mL* (1 mol / 342.30 g) = 0.0000292 mol

 
> 20 mL of a 5.0 M sucrose solution 

5.0 M * 0.020 L = 0.1 mol

2,000 mL of a 5.0 ppm sucrose solution

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"