Chemistry Questions & Answers

1. Diez litros de hidrogeno a 1 atmósfera de presión están contenidos en un cilindro que tiene un pistón móvil. El pistón se mueve hasta que la misma masa de gas ocupa 2 litros a la misma temperatura, encuentre la presión en el cilindro, exprésela er mmHg .

In \( \mathrm{Cr}_{2} \mathrm{O}_{7}{ }^{2-} \), the oxidation state of Cr is \( \square \) and \( \mathrm{O}_{\text {is }} \square \)

3 Ajustar (balancear) las ecuaciones químicas siguientes: a) \( \mathrm{Cr}+\mathrm{H}_{2} \mathrm{~S} \rightarrow \mathrm{Cr}_{2} \mathrm{~S}_{3}+\mathrm{H}_{2} \) b) \( \mathrm{CH}_{4}+\mathrm{O}_{2} \rightarrow \mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O} \) c) \( \mathrm{Ni}(\mathrm{OH})_{3}+\mathrm{H}_{2} \mathrm{MnO}_{4} \rightarrow \mathrm{Ni}_{2}\left(\mathrm{MnO}_{4}\right)_{3}+\mathrm{H}_{2} \mathrm{O} \) d) \( \mathrm{C}_{3} \mathrm{H}_{8}+\mathrm{O}_{2} \rightarrow \mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O} \) e) \( \mathrm{Pb}(\mathrm{OH})_{4}+\mathrm{HCl} \rightarrow \mathrm{PbCl}_{4}+\mathrm{H}_{2} \mathrm{O} \) f) \( \mathrm{CsOH}+\mathrm{H}_{2} \mathrm{Se} \rightarrow \mathrm{Cs}_{2} \mathrm{Se}+\mathrm{H}_{2} \mathrm{O} \)

\( H _ { 2 } SO _ { 4 } + Cu \rightarrow CuSO _ { 4 } + H _ { 2 } \)

Elements \( X \) and \( Y \) from the first transition series, both of them have compounds used in cosmetics industry so they lie in group......... \& ....... (Quiz \( 1 \mathrm{LICh1} \) ) a) \( 1 \mathrm{~B}, 7 \mathrm{~B} \) b) \( 18,2 B \) c) \( 4 B, 2 B \) d) \( 38,7 B \)

What is the group number? \( \quad \) What is the generic outer electron configuration

Identify the group number and generic outer electron configuration for a neutral main-group element with the following two What is the group number? \( \quad \) What is the generic outer electron configuration?

Identify the group number and generic outer electron configuration for a neutral main-group element with the following two What is the group number? \( 1 \mathrm{~A}(1) \) \( 3 \mathrm{~A}(13) \)

(a) List three oxyanions that have a -1 charge. (b) List two oxyanions that have a -2 charge. (c) List one oxyanion that has a -3 charge.

A sample of argon gas at STP occupies 56.2 liters. Determine the number of moles of argon and the mass in the sample.