A mixture of $\mathrm{HCOOH}$ and ${\mathrm{H}}_2{\mathrm{C}}_2{\mathrm{O}}_4$ is heated with concentrated ${\mathrm{H}}_2{\mathrm{SO}}_4$. The gas produced is collected and on treating with $\mathrm{KOH}$ solution, the volume of the gas decreases by $1/6^{\mathrm{th}}$. Calculate the molar ratio of two acids in the original mixture. If the ratio comes out to be a:b, report your answer as 'a+b'.

In the following reaction:

$\mathrm{A}+2\mathrm{B}+3\mathrm{C}\rightleftharpoons \mathrm{A}{\mathrm{B}}_2{\mathrm{C}}_3$
$6.0 \mathrm{g}$ of $\mathrm{A}$, $6.0\times {10}^{23}\mathrm{ }$ atoms of $\mathrm{B}$ and $0.036 \mathrm{mol}$ of $\mathrm{C}$ reacted and formed $4.8 \mathrm{g}$ of compound $\mathrm{A}{\mathrm{B}}_2{\mathrm{C}}_3$. If the atomic mass of $\mathrm{A}$  and $\mathrm{C}$ are $60$ and $80 \mathrm{amu}$, respectively. What is the atomic mass of $\mathrm{B}$ in $\mathrm{amu}$? (Avogadro number$=6\times {10}^{23}$)

A gaseous hydrocarbon on combustion gives $0.72 \mathrm{g}$ of water and $3.08 \mathrm{g}$ ${\mathrm{CO}}_2$. What is the empirical formula of the hydrocarbon?

Galena (an ore) is partially oxidized by passing air through it at high temperature. After some time, the passage of air is stopped, but the heating is continued in a closed furnace such that the contents undergo self-reduction. The weight (in $\mathrm{kg}$) of $\mathrm{Pb}$ produced per $\mathrm{kg}$ of ${\mathrm{O}}_2$ consumed is ____. (Atomic weights in $\mathrm{g}\mathrm{ }{\mathrm{mol}}^{-1}: \mathrm{O}=16,\mathrm{ }\mathrm{S}=32,\mathrm{ }\mathrm{Pb}=207$)

Give the answer to the nearest integer value.

If the reaction sequence given below is carried out with $15$ moles of acetylene, the amount of the product $\mathrm{D}$ formed (in $\mathrm{g}$) is

The yields of $\mathrm{A},\mathrm{B},\mathrm{C}$ and $\mathrm{D}$ are given in parentheses.

[Given: Atomic mass of $\mathrm{H}=1,\mathrm{C}=12,\mathrm{O}=16,\mathrm{Cl}=35$]

${\mathrm{NaClO}}_3$ is used, even in spacecrafts, to produce ${\mathrm{O}}_2.$ The daily consumption of pure ${\mathrm{O}}_2$ by a person in $492 \mathrm{L}$ at $1$ atm, $300\mathrm{K}.$ How much amount of ${\mathrm{NaClO}}_3,$ in grams, is required to produce ${\mathrm{O}}_2$ for the daily consumption of a person at $1$ atm, $\mathrm{}300\mathrm{K}$ ? 

${\mathrm{NaClO}}_3\left(\mathrm{s}\right)+\mathrm{Fe}\left(\mathrm{s}\right)\to {\mathrm{O}}_2\left(\mathrm{g}\right)+\mathrm{NaCl}\left(\mathrm{s}\right)+\mathrm{FeO}\left(\mathrm{s}\right)$
$\mathrm{R}=0.082 \mathrm{L} \mathrm{atm} {\mathrm{mol}}^{-1} {\mathrm{K}}^{-1}$

Give answer to the nearest integer value.

The ammonia is prepared by treating ammonium sulphate with calcium hydroxide is completely used by ${\mathrm{NiCl}}_2\mathbf{·}6{\mathrm{H}}_2\mathrm{O}$ to form a stable coordination compound. Assume that, both the reactions are $100\%$ completed. If $1584 \mathrm{g}$ of ammonium sulphate and $952 \mathrm{g}$ of ${\mathrm{NiCl}}_2\mathbf{·}6{\mathrm{H}}_2\mathrm{O}$ are used in the preparation, the combined weight (in grams) of gypsum and the nickel ammonia coordination compound produced is ____.

Atomic weights in $\mathrm{g}\mathrm{ }{\mathrm{mol}}^{-1}$:

$$\begin{gathered} \mathrm{H}=1;\mathrm{ }\mathrm{N}=14\mathrm{ } \\ \mathrm{O}=16; \mathrm{S}=32\mathrm{ } \\ \mathrm{Cl}=35.5;\mathrm{ }\mathrm{Ca}=40\mathrm{ } \\ \mathrm{Ni}=59 \end{gathered}$$

In the following reaction

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The $\%$ yield for reaction $\mathrm{I}$ is $60\%$ and that of reaction II is $50\%$. The overall yield of the complete reaction is$\%$