When a $1.0 \, g$ mixture of $NaHCO_3$ and $Na_2CO_3$ is heated at $150^{\circ}C$,$112.0 \, mL$ of $CO_2$ is produced at $STP$. Calculate the percentage of $Na_2CO_3$ in the mixture. $(Na = 23, C = 12, O = 16)$

The hardness of a water sample containing $10^{-3} \; M \; MgSO_{4}$ expressed as $CaCO_{3}$ equivalents (in $ppm$) is (molar mass of $MgSO_{4}$ is $120.37 \; g/mol$)

The composition of a sample of wustite is $Fe_{0.93} O_{1.00}$. The percentage of iron in the form of $Fe^{3+}$ ion is nearly:

How many grams of $NaOH$ will be required to prepare $250 \, mL$ of $0.1 \, M$ solution?

The ratio of the molar amounts of $H_2S$ needed to precipitate the metal ions from $20 \ mL$ each of $1 \ M \ Cd(NO_3)_2$ and $0.5 \ M \ CuSO_4$ is

$0.1 \ M$ solution of $KI$ reacts with excess of $H_2SO_4$ and $KIO_3$ solution. According to the equation $5I^{-} + IO_3^{-} + 6H^{+} \rightarrow 3I_2 + 3H_2O$. Identify the correct statements $:$
$(A)$ $200 \ mL$ of $KI$ solution reacts with $0.004 \ mol$ of $KIO_3$.
$(B)$ $200 \ mL$ of $KI$ solution reacts with $0.006 \ mol$ of $H_2SO_4$.
$(C)$ $0.5 \ L$ of $KI$ solution produced $0.005 \ mol$ of $I_2$.
$(D)$ Equivalent weight of $KIO_3$ is equal to $\frac{\text{Molecular weight}}{5}$.
Choose the correct answer from the options given below $:$