$A$ metal chloride contains $49.5\%$ chlorine. The specific heat of the metal is $0.064 \ cal \ g^{-1} \ ^\circ C^{-1}$. What is the exact atomic weight of the metal?

Use the data given in the following table to calculate the molar mass of naturally occurring argon isotopes:

Isotope	Isotopic molar mass $(g \, mol^{-1})$	Abundance (%)
$^{36}Ar$	$35.96755$	$0.337$
$^{38}Ar$	$37.96272$	$0.063$
$^{40}Ar$	$39.9624$	$99.600$

If $M_1$ and $M_2$ are the molecular weights of $Al(OH)_3$ and $H_3PO_3$ respectively,find their equivalent weights in the following reaction:
$Al(OH)_3 + 2H_3PO_3 \to Al(OH)(H_2PO_3)_2 + 2H_2O$

Elements $X$ and $Y$ form compounds $X_2Y_3$ and $X_3Y_4$ respectively. If $0.2 \ mol$ of $X_2Y_3$ weighs $32.0 \ g$ and $0.4 \ mol$ of $X_3Y_4$ weighs $92.8 \ g$,then the atomic masses of $X$ and $Y$ are respectively:

The modern basis of atomic weight is

$0.45 \ g$ of an acid (mol wt. $= 90$) required $20 \ mL$ of $0.5 \ N$ $KOH$ for complete neutralization. The basicity of the acid is: