Química preguntas y respuestas

2 mole of an ideal gas at \( 27^{\circ} \mathrm{C} \) temperature is expanded reversibly from 2 lit to 20 lit. Find the entropy change. \( (R=2 \mathrm{cal} / \mathrm{mol} \mathrm{K}) \) \( \begin{array}{llll}\text { (a) } 92.1 & \text { (b) } 0 & \text { (c) } 4 & \text { (d) }-9.2\end{array} \)

What is the entropy change (in \( \mathrm{JK}^{-1} \mathrm{~mol}^{-1} \) ) when one mole of ice is converted into water at \( 0^{\circ} \mathrm{C} \) ? (The enthalpy change for the conversion of ice to liquid water is \( 6.0 \mathrm{~kJ} \mathrm{~mol}^{-1} \) at \( 0^{\circ} \mathrm{C} \) ) \( \begin{array}{llll}\text { (a) } 21.98 & \text { (b) } 20.13 & \text { (c) } 2.013 & \text { (d) } 2.198\end{array} \)

The molar entropies of \( \mathrm{HI}(\mathrm{g}) \) and \( \mathrm{I}(\mathrm{g}) \) at 298 K are 206.5 114.6 , and \( 180.7 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1} \) respectively. Using the \( \Delta \mathrm{G}^{\circ} \) given below, calculate the bond energy of HI . \( \mathrm{HI}(\mathrm{g}) \longrightarrow \mathrm{H}(\mathrm{g})+\mathrm{I}(\mathrm{g}) ; \Delta \mathrm{G}^{\circ}=271.8 \mathrm{~kJ} \) \( \begin{array}{ll}\text { (a) } 282.4 \mathrm{~kJ} \mathrm{~mol}^{-1} & \text { (b) } 298.3 \mathrm{~kJ} \mathrm{~mol}^{-1} \\ \text { (c) } 290.1 \mathrm{~kJ} \mathrm{~mol}^{-1} & \text { (d) } 315.4 \mathrm{~kJ} \mathrm{~mol}^{-1}\end{array} \)

Which pair of chemicals is capable of forming a buffer solution? (A) HCl and NaCl (B) \( \mathrm{HNO}_{2} \) and KNO 2 (C) KCl and NaF (D) HBr and \( \mathrm{NH}_{3} \)

Questions Check Answers How many milliliters of a 6.0 M HCl solution will provide 164 g of HCl ? Answer: 750 mL of HCl solution

A 28.95 mL sample of HCl of unknown concentration is transferred to a flask, where a few drops of indicator solution are added. The solution is titrated with 1.9 M NaOH . After 11.5 mL are added, the indicator turns pink, showing that the equivalence point has been reached. Calculate the molarity of the acid.

Question 8 What is the pH of a solution with \( \mathrm{pOH}=8.13 \) ? Add your answer

Buttermilk is the example of homogeneous or heterogeneous mixture?

Write the balanced chemical equation for the reaction of khp with naoh.

What is the concentration of \( \mathrm{H}+ \) ions in a solution with a pH of 12.84 ? Enter your answer in scientific notation to be recognized by autograding. For example: \( 8.4 \times 10-9 \) should be entered as " \( 8.4 \mathrm{e}-9 \) " in Blackboard. Add your answer