$K_2CS_3$ is called potassium ...... .

$A + 2B \rightarrow AB_{2}$. $36.0 \ g$ of '$A$' (Molar mass: $60 \ g \ mol^{-1}$) and $56.0 \ g$ of '$B$' (Molar mass: $80 \ g \ mol^{-1}$) are allowed to react. Which of the following statements are correct?
$(A)$ '$A$' is the limiting reagent
$(B)$ $77.0 \ g$ of $AB_{2}$ is formed
$(C)$ Molar mass of $AB_{2}$ is $220 \ g \ mol^{-1}$
$(D)$ $15.0 \ g$ of '$A$' is left unreacted after the completion of reaction.
Choose the correct answer from the options given below:

Bleaching powder and bleach solution are produced on a large scale and used in several household products.
The effectiveness of bleach solution is often measured by iodometry.
$1.$ $25 \ mL$ of household bleach solution was mixed with $30 \ mL$ of $0.50 \ M \ KI$ and $10 \ mL$ of $4 \ N$ acetic acid. In the titration of the liberated iodine,$48 \ mL$ of $0.25 \ N \ Na_2S_2O_3$ was used to reach the end point. The molarity of the household bleach solution is
$(A)$ $0.48 \ M$ $(B)$ $0.96 \ M$ $(C)$ $0.24 \ M$ $(D)$ $0.024 \ M$
$2.$ Bleaching powder contains a salt of an oxoacid as one of its components. The anhydride of that oxoacid is
$(A)$ $Cl_2O$ $(B)$ $Cl_2O_7$ $(C)$ $ClO_2$ $(D)$ $Cl_2O_6$
Give the answer for question $1$ and $2.$

$A$ metal oxide contains $75 \%$ metal by mass. If the vapour density of the metal chloride is $89$,what is the atomic weight of the metal?

The more commonly used baking powder contains about $30\%$ $NaHCO_3$,$20\%$ $NaAl(SO_4)_2$,$10\%$ $Ca(H_2PO_4)_2$ and $40\%$ starch. Which of the following statements is/are correct?

Which of the following is $NOT$ true for $1 \ g$ of Helium?