Which metal bicarbonates do not exist in the solid state?
$(i) \, LiHCO_3$
$(ii) \, Ca(HCO_3)_2$
$(iii) \, Zn(HCO_3)_2$
$(iv) \, AgHCO_3$

Which metal is not silvery white?

Which of the following statements is correct?

Given below are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: The alkali metals and their salts impart characteristic colour to reducing flame.
Reason $R$: Alkali metals can be detected using flame tests.
In the light of the above statements,choose the most appropriate answer from the options given below.

$CO_2 + NH_3 + H_2O \to X$
$X + NaCl \to Y + NH_4Cl$
$2Y \xrightarrow{\Delta} Z + H_2O + CO_2$. '$Z$' is

$A + H_2O \to NaOH$; $A$ $\xrightarrow[400 \ ^oC]{O_2} B$ $\xrightarrow[25 \ ^oC]{H_2O} NaOH + O_2$
$B$ is used for oxygenating in submarines. $A$ and $B$ are: