$A$ gas has a density of $2.68 \ g/L$ at $STP$. Identify the gas.

If one liter of air is repeatedly passed over heated copper and magnesium until no further reduction in volume occurs,the final volume of the air will be approximately ......... $mL$.

How many moles of aluminum oxide $(Al_2O_3)$ are produced when $1 \text{ mole}$ of potassium chlorate $(KClO_3)$ undergoes thermal decomposition,and the resulting gaseous product is reacted with excess aluminum?

What is the approximate volume occupied by $22.4 \, L$ of water vapor at $STP$ when it is condensed into liquid water?

Fill in the blanks given below:
$(i)$ The mass of $1$ mole of a substance expressed in grams is called its .........
$(ii)$ The amount of solute dissolved in $1$ $kg$ of solvent is called its .........
$(iii)$ The Fahrenheit scale in a thermometer is marked between .........
$(iv)$ In $NaCl$,each $Na^{+}$ ion is surrounded by ......... $Cl^{-}$ ions.

All reactions which involve chemical disintegration are: