Chemistry Questions & Answers

What initial volume of a \( 15 \%(\mathrm{~m} / \mathrm{v}) \) mannose solution is needed to prepare 125 mL of a \( 3.0 \% \) \( (\mathrm{~m} / \mathrm{v}) \) mannose solution?

(c) Metals have a metallic bond. (1) Describe metallic bonding in sodium metal.

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? \( 1 \mathrm{~A}(1) \) \( 3 \mathrm{~A}(13) \)