b) qual é o número de valência dos elementos?

b) qual é o número de valência dos elementos?

Upon thermal decomposition of X, a black compound was expected, but a red compound was found instead, what might be the reason? (Exam 1 L2 Ch2) a) condition of (absence of air ) was not properly applied b) the temperature applied was not sufficient c) the wrong compound was thermally decomposed instead of the correct one d) both a and c are correct

Calculate the density of a cup of tap water at room temperature with a mass of 50.8 g and a volume of 52.1 mL . Round your answer to the appropriate number of sig figs. \( 0.975 \mathrm{~g} / \mathrm{mL} \) \( 1.0 \mathrm{~mL} / \mathrm{g} \)

2. Determine el número de oxidación del elemento indicado en cada una de las sustancias siguientes: a) Ti en \( \mathrm{TiO}_{2} ; \) b) Sn en \( \mathrm{SnCl}_{4} ; \) c) C en \( \mathrm{C}_{2} \mathrm{O}_{4}^{2-} ; \) d) N en \( \left(\mathrm{NH}_{4}\right) \mathrm{SO}_{4} ; \) e) N en \( \mathrm{HNO}_{2} ; \) f) Cr en \( \mathrm{Cr}_{2} \mathrm{O}_{7}^{2-} \)

d) \( \mathrm{C}_{4} \mathrm{H}_{10} \mathrm{O}+\mathrm{O}_{2} \rightarrow \quad \mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O} \)