$10 \ g$ of a solute is dissolved in $90 \ g$ of a solvent. Its mass percent in solution is

$1000 \ g$ aqueous solution of $CaCO_3$ contains $10 \ g$ of carbonate. Concentration of the solution is .......... $ppm$.

What is the concentration of nitrate ions if equal volumes of $0.1 \, M$ $AgNO_3$ and $0.1 \, M$ $NaCl$ are mixed together (in $, M$)?

The mole fraction of a solute in a $100$ molal aqueous solution is $.......... \times 10^{-2}$ (Round off to the nearest integer). [Given: Atomic masses: $H = 1.0 \ u$,$O = 16.0 \ u$]

Which among the following is a unitless physical quantity?

What is the mole fraction of water in a spirit sample containing $92\%$ ethyl alcohol by mass?