Fresh features from the #1 AI-enhanced learning platform.Try it free
Fresh features from the #1 AI-enhanced learning platformCrush your year with the magic of personalized studying.Try it free
Question

# Patients undergoing an upper gastrointestinal tract laboratory test are typically given an X-ray contrast agent that aids with the radiologic imaging of the anatomy. One such contrast agent is sodium iatrizoate, a nonvolatile water soluble compound. A 0.378-m solution is prepared by dissolving 38.4 g of sodium diatrizoate (NaDTZ) in $1.60 \times 10 ^ { 2 }\ \mathrm { mL }$ of water at $31.2 ^ { \circ } \mathrm { C }$ (the density of water at $31.2 ^ { \circ } \mathrm { C }$ is 0.995 g/mol). What is the molar mass of sodium diatrizoate? What is the vapor pressure of this solution if the vapor pressure of pure water at $31.2 ^ { \circ } \mathrm { C }$ is 34.1 torr?

Solution

Verified
Step 1
1 of 4

To determine the molar mass of sodium diatrizoate (NaDTZ) we need to know the mass and number of moles of sodium diatrizoate.

Before we calculate the moles of NaDTZ, we need to calculate the mass, and moles of water.

$\textit{mass}$(H$_2$O) = $\textit{d}$ $\times$ $\textit{V}$ = 0.995g/mL $\times$ 160 mL = 0.159 kg

$\textit{n}$(H$_2$O) = $\dfrac{mass}{Molar mass}$ = $\dfrac{159g}{18.016}$ = 8.83 mol

We have the mass of NaDTZ - 38.4 g, so we need to determine the number of moles. The number of moles can be calculated from molality.

$\textit{m}$ = $\dfrac{n(NaDTZ)}{mass(H_2O}$

$\textit{n}$(NaDTZ) = $\textit{m}$ $\times$ $\textit{mass}$(H$_2$O)

$\textit{n}$(NaDTZ) = 0.378 mol/kg $\times$ 0.159 kg = 0.060 mol

## Recommended textbook solutions #### Chemistry: The Molecular Nature of Matter and Change

7th EditionISBN: 9780073511177Patricia Amateis, Silberberg
6,031 solutions #### Chemistry

9th EditionISBN: 9781133611097 (10 more)Steven S. Zumdahl, Susan A. Zumdahl
5,853 solutions #### Chemistry

10th EditionISBN: 9781305957404Donald J. DeCoste, Steven S. Zumdahl, Susan A. Zumdahl
6,073 solutions #### Chemistry, AP Edition

10th EditionISBN: 9781305957732 (1 more)Donald J. DeCoste, Steven S. Zumdahl, Susan A. Zumdahl
6,061 solutions