A bottle of oleum is labelled as $109\%.$ Which of the following statement is/are correct for this oleum sample?

Which of the following numbers have same significant figures?

The natural titanium oxide, known as rutile and containing $39.95\%$ of oxygen, is isomorphous with ${\mathrm{SnO}}_2,$ known as cassiterite. Calculate the atomic weight of titanium.

Give the answer up to first place of decimal.

When a mixture of $\mathrm{NaBr}$ and $\mathrm{NaCl}$ is repeatedly digested with sulphuric acid, all the halogens are expelled and ${\mathrm{Na}}_2{\mathrm{SO}}_4$ is formed quantitatively. With a particular mixture, it was found that the weight of ${\mathrm{Na}}_2{\mathrm{SO}}_4$ obtained was precisely the same as the weight of $\mathrm{NaBr}-\mathrm{NaCl}$ mixture taken. Calculate the ratio of the weights of $\mathrm{NaCl}$ and $\mathrm{NaBr}$ in the mixture.

Give the final answer up to two places of decimal.

One litre of an acidified solution of ${\mathrm{KMnO}}_4$ containing $15.8 \mathrm{g}$ of ${\mathrm{KMnO}}_4$ is decolourised by passing a sufficient amount of ${\mathrm{SO}}_2$. If ${\mathrm{SO}}_2$ is produced by roasting of iron pyrites $\left({\mathrm{FeS}}_2\right)$, what will be the amount of pyrites (in grams) required to produce the necessary amount of ${\mathrm{SO}}_2$?

(Atomic mass of $\mathrm{K}=39, \mathrm{Mn}=55, \mathrm{S}=32, \mathrm{O}=16, \mathrm{Fe}=56, \mathrm{H}=1$)

Round off your answer to the nearest integer.

A $0.239 \mathrm{g}$ sample of an unknown organic base is dissolved in water and titrated with a $0.135 \mathrm{M} \mathrm{HCl}$ solution. After the addition of $18.35 \mathrm{mL}$ of an acid, a $\mathrm{pH}$ of $10.73$ is recorded. The equivalence point is reached when a total of $39.24 \mathrm{mL}$ of $\mathrm{HCl}$ is added. The base and the acid combine in a $1: 1$ratio. What is the molar mass $\left(\text{in} \mathrm{g} {\mathrm{mol}}^{-1}\right)$ of the organic base?

Answer correct up to two places of decimals after proper rounding off.

$2.10 \mathrm{g}$ of mixture of ${\mathrm{NaHCO}}_3$ and ${\mathrm{KClO}}_3$ requires $100 \mathrm{mL}$ of $0.1 \mathrm{N} \mathrm{HCl}$  for complete reaction. If $\mathrm{x} \mathrm{g}$ of residue that would be obtained on strongly heating $2.20 \mathrm{g}$ of the same mixture then, determine the value of $\mathrm{x} \mathrm{g}$.

Give an answer to the nearest integer value.