Arrange the following aqueous solutions, each 10% by mass in solute, in order of decreasing boiling point: glucose (c6h12o6), sucrose (c12h22o11), sodium nitrate (nano3).

NaNO₃ > C₆H₁₂O₆ > C₁₂H₂₂O₁₁

Explanation:

Boiling-point elevation is defined as the phenomenon where boiling point of a liquid will be higher when another compound is added, meaning that a solution has a higher boiling point than a pure solvent. The formula is:

ΔT = k×m×i

Where k is ebulloscopic constant of the solvent, m is molality of solution in moles of solute per kg of solution and i is Van't Hoff factor (1 in glucose and sucrose and 2 in sodium nitrate).

Molality is proportional to moles of solute. As the solutions have the same concentration in mass, the lowest molar mass of solute, the highest boiling point elevation.

Molar mass of glucose is 180,2 g/mol; sucrose 342,3 g/mol and sodium nitrate 85 g/mol.

As sodium nitrate has the lowest molar mass and a Van't Hoff factor of 2, its solution will have the highest boiling point, then will be glucose (In order to its molar mass), and the lowest boiling point will be sucrose. Thus, in order of decreasing boiling point:

NaNO₃ > C₆H₁₂O₆ > C₁₂H₂₂O₁₁

I hope it helps!

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

a physical change biology

explanation: