Which of the following is an example of anionic interference in atomic emission spectroscopy? O Interference of high concentration of sodium ions in assay calcium ions. Interference by formation of less volatile salt with sulphat by calcium. Decreased drop size of the analyte solution by alcohols.

A chemist carefully measures the amount of heat needed to raise the temperature of a 510.0 mg sample of a pure substance from \( 2.9^{\circ} \mathrm{C} \) to \( 23.7^{\circ} \mathrm{C} \). The experiment shows that 25.9 J of heat are needed. What can the chemist report for the specific heat capacity of the substance? Be sure your answer has the correct number of significant digits.

If 82 g of sugar is dissolved in 7950 mL of water, what is the concentration of the solution?

10.- ¿Cuántos átomos de sodio hay en 4,35 moles de sodio? Dato masa atómica sodio \( =23 \mathrm{~g} / \mathrm{mol} \) R.- \( 2,61 \times 10^{24} \) átomos

Actividad 3. Composición porcentual y Rendimiento de Reacción. (15 puntos) 1. Calcula la composición porcentual de cada elemento en los siguientes compuestos: a) \( \mathrm{AgNO}_{3} \) b) \( \mathrm{C}_{2} \mathrm{H}_{6} \mathrm{O} \)

При образовании 2,2г СО \( { }_{2} \) по уравнению реакции: \( \mathrm{C}(\mathrm{тв})+\mathrm{O}_{2}=\mathrm{CO}_{2}(\mathrm{r}) \) выделилось 19,7 кДж теплоты. Стандартная энтальпия образования \( \mathrm{CO}_{2}(\mathrm{r}) \) в кДж/ моль равна -197 +394 +197 \( -394 \times \)