Equal masses of $SO_2$,$CH_4$,and $O_2$ are placed in an empty container at $298 \ K$. The total pressure is $2.1 \ atm$. What is the partial pressure of $CH_4$ in the mixture in $atm$?

An ideal gas mixture of $C_2H_6$ and $C_2H_4$ occupies a volume of $28 \ L$ at $1 \ atm$ and $273 \ K$. This mixture reacts completely with $128 \ g$ of $O_2$ to produce $CO_2$ and $H_2O_{(l)}$. What is the mole fraction of $C_2H_4$ in the mixture?

$20 \ mL$ of sodium iodide solution gave $4.74 \ g$ silver iodide when treated with excess of silver nitrate solution. The molarity of the sodium iodide solution is $........ M$. $(Nearest \ Integer \ value)$
$(Given: Na=23, I=127, Ag=108, N=14, O=16 \ g \ mol^{-1})$

$120 \ g$ of urea are present in $5 \ L$ of solution. The active mass of urea is:

What volume in liters is required to prepare a $0.1 \ N$ $HNO_3$ solution from $6.3 \ g$ of $HNO_3$?

The minimum amount of $O_2\,(g)$ consumed per gram of reactant is for the reaction: (Given atomic mass: $Fe = 56, O = 16, Mg = 24, P = 31, C = 12, H = 1$)